None
u 238.20 Lanthanum Lead La Pb 139.000 207.200 Vanadium Xenon V Xe 51.00 130 . 20 Lithium Lutecium Li Lu 6.940 175.000 Ytterbium (Neoytterbium) Yttrium Yb Yt 173.50 88.70 Magnesium Manganese Mg Mn 24.320 54.930 Zinc Zirconium Zn Zr 65.37 90.60 Mercury He 200 600 244 MANUAL OF CYANIDATION WEIGHTS AND MEASURES, ENGLISH AND AMERICAN SYSTEM Linear Measure 12 inches 1 foot 3 feet : lyard 5 . 5 yards , 1 rod 40 rods 1 furlong 8 furlongs 1 mile Inches Feet Yards Rods Furlongs Mile 36 3.0 1.0 198 16.5 5.5 1 7920 660.0 220.0 40 1 63,360 5280.0 1760.0 320 8 1 Square Measure 144 square inches . 1 square foot 9 square feet 1 square yard 30^ square yards 1 square rod 160 square rods 1 acre 640 acres 1 square mile Cubic Measure 1728 cubic inches 1 cubic foot 27 cu. feet 1 cubic yard Avoirdupois Weight English 437 . 5 grains 1 ounce (oz.) 16 ounces 1 pound (Ib.) 14 pounds 1 stone (st.) 28 pounds 1 quarter (qr.) 112 pounds 1 hundredweight (cwt.) 20 cwt. (2240 Ib.) 1 ton (T.) American 437 . 5 grains 1 ounce (oz.) 16 ounces 1 pound (Ib.) 100 pounds 1 hundredweight (cwt.) 20 cwt. (2000 Ib.) 1 ton (T.) TABLES 245 Troy Weight 24 grains 1 pennyweight (dwt.) 20 pennyweights 1 ounce (oz). 12 ounces 1 pound (Ib.) 1 Ib. Troy 5760 grains 14.5833 oz. Troy 1 Ib. avoirdupois 29,166.6 oz. Troy 2000 Ib. avoirdupois Liquid Measure 4 gills 1 pint 2 pints 1 quart 4 quarts : 1 gallon 1 U. S. gallon— 231 cu. in.— 0.134 cu. ft. 1 cu. ft.— 7 . 481 U. S. gallons 1 British imperial gallon — 277 . 274 cu. in. — 0 . 16046 cu. ft. 1 cu. ft. — 6 . 234 imperial gallons 1 cu. ft 62.42 Ib. of water 1 ton (2000 Ib.) 32.04 cu. ft. of. water 1 ton (2000 Ib.) 239.69 U. S. gallons THE METRIC SYSTEM Linear Measure 10 millimeters (mm.) 1 centimeter (cm.) 10 centimeters 1 decimeter (dm.) 10 decimeters 1 meter (m.) 10 meters 1 decameter (Dm.) 10 decameters 1 hectometer (Hm.) 10 hectometers . 1 kilometer (Km.) Square Measure 100 square millimeters (mm.2) 1 square centimeter (cm.2) 100 square centimeters 1 square decimeter (dm.2) 100 square decimeters 1 square meter (m.2) Cubic Measure 1000 cubic millimeters (mm.3) 1 cubic centimeter (cm.3 or cc) 1000 cubic centimeters 1 cubic decimeter (dm.3) 1000 cubic decimeters 1 cubic meter (m.3) 246 MANUAL OF CYANIDATION Liquid Measure 10 millilitres (ml.) 1 centilitre (cl.) 10 centilitres 1 decilitre (dl.) 10 decilitres 1 litre (1.) 10 litres 1 decalitre (Dl.) 10 decalitres 1 hectolitre (HI.) 10 hectolitres 1 kilolitre (Kl.) 1 litre 1000 cubic centimetres " 1 cu. ft. of water 28.317 litres 1 litre of water 61.023 cu. in. = 0.03531 cu. ft. 1 metric ton of water 35.319 cu. ft. 1 metric ton of water 264.2 U. S. gallons Measure of Weight 10 milligrams (mg.) 1 centigram (eg.) 10 centigrams 1 decigram (dg.) 10 decigrams 1 gram (g.) 10 grams 1 decagram (Dg.) 10 decagrams 1 hectogram (Hg.) 10 hectograms 1 kilogram (Kg.) 1000 kilograms 1 ton (T.) 1 gram = the weight of 1 cubic centimeter of pure distilled water at a temperature of 4° cent. 1 kilogram = the weight of 1 litre of water 1 ton = the weight of 1 cubic meter of water CONVERSION TABLES Linear Measure 1 in 2.53998 cm. 1 cm 0.3937043 in. 1ft 0.30479m. 1m 39. 37043 in. lyd 0.914399m. 1m 3.28083ft. Imi 1.60934km. 1m 1.09362yd. 1km 0.62137 mi. Square Measure 1 centar (1 sq. m.) 1550 sq. in. — 10. 764 sq. ft. 1 ar 119. 6 sq. yd. 1 hectar 2 . 47104 acres 1 sq. cm 0 . 155 sq. in. 1 sq. meter 10 . 76390 sq. ft. 1 sq. km 0.3861 sq. mi. 1 acre 0.40469 hectar 1 sq. in 6 . 4516 sq. cm. 1 sq. ft 0.092903 sq. m. TABLES 247 Cubic Measure 1 cu. in 16.38720 cc 1 cc 0. 06102376 cu. in. 0. 0000353 cu. ft. 1 cu. ft 0.028317 cu. m. 1 cu. ra 35.31445 cu. ft. 1. 30794 cu. yd. 1 cu. yd ! 0 . 764553 cu. m. Liquid Equivalents 1 fluid ounce 29 . 5737 millilitres 1 millilitre 0.03381 fluid ounce — 0.061027 cubic inch 1 quart 0 . 94636 litres 1 litre 1 .0567 quarts 1 U. S. gallon 3.78543 litres 1 litre 0.26417 gallons Dry Equivalents 1 hectolitre 2 . 8377 bushels 1 U. S. bushel 0. 35239 hectolitres Weight oz. avoirdupois 28.34954 grams Ib. avoirdupois 453 . 59 grams (short) ton 907. 18 kg. gram 0.035274 oz. avoir. — 0.00220 Ib. kg 35.27392 oz. avoir.— 2 . 2046223 Ib. metric ton 1 . 102311 short ton — 0 . 9842 long T. grain 64 . 799 mg. dwt 1 . 55518 grams oz. Troy 31 . 1035 grams Ib. Troy 0.37324 kg. gram 15 . 4324 grains — 0 . 64301 dwt. gram 0.03215 oz. Troy I kg 32. 15076oz. Troy— 2. 67923 Ib. Troy 1 oz. Troy per ton'of 2000 Ib. — 34.285 grams per metric ton 248 MANUAL OF CYANIDATION TABLE 30. — ASSAY CONVERSION TABLE Per cent. Grams per metric ton (1000 kilos) Oz. Troy per lone ton (2240 lb.) Oz. Troy per metric ton (2204. 6 lb.) Oz. Troy per short ton (2000 lb.) 1 00000 10000 00 326 66600 321 50700 291 66600 gram per metric ton oz Troy per long ton 0.00010 0 00300 1.00000 30 61200 0.03266 1 00000 0.03215 0 98420 0.02916 0 89280 oz Troy per metric ton 0 00310 31 . 10348 1 01600 1 00000 0 90710 oz. Troy per short ton dollar per short ton (gold at $20 67 per oz.) 0.00340 0.00016 34 . 28500 1.66000 1.12000 0.05400 1 . 10200 0.05300 1 . 00000 0 04800 VARIOUS FORMULAS Area of a Circle Radius2 X 3.1416 or Diameter2 X 0.7854 Circumference of a Circle Diameter X 3.1416 Cubic Contents of Cylindrical Tank Area X depth Cubic Contents of Cone Area of base — » — - X depth CALCULATION OF RECOVERY IN CONCENTRATE Let C = assay value of concentrate I<et H = assay value of head Let T = assay value of tailing Let R = Ratio of concentration Let W = weight of concentrate (per cent.) Let P = percentage recovery Let L = percentage loss in tailing C - T R = W = P = P = L = H - T 100 X C(H - T) H(C-T) C X 100 HXR 100 X T(C - H) H (C - T) TABLES 249 Elimination of Middling by Calculation. — This is based on the assumption that the return of the middling to the head of the concentration system does not change the subsequent assay value of the concentrate and tailing. The weights of the various products and the assay of the middling need not be known. Let X and Y = percentage weights of concentrate and tailing respectively when middling is eliminated. Let h, c, t, = assay values of head concentrate and tailing respectively. Let x and y = percentage of total values in concentrate and tailing when middling is eliminated. x = 100 (h - 0 _ c - t 100 (h - t)c h(c - t) Y 100(c - h) c - t 100(c - h)t h(c - t) Power. I.H.P.— 33,000 foot-pounds per minute = 4562.33 kilogram meters per minute = 0.745941 kilowatts = 1.01385 metric h.p. 1 metric h.p. = 32,549 foot-pounds per minute = 4.500 kilogram meters per minute = 0.735750 kilowatt = 0.98634 h.p. Pressure. — 1 atmosphere = 760 millimeters, or 29.922 inches of mercury column = 10.333 meters, or 33.901 feet of water column = 14.696 pounds per square inch = 1.0333 kilos per square centimeter. 1 pound per square inch = 0.070310 kilo per square centimeter. 1 kilo per square centimeter = 14.223 pounds per square inch. TABLE 31. — MISCELLANEOUS FIGURES ON THE WEIGHT OF BROKEN ORE (Richards "Ore Dressing", Weight per cubic foot, Ib. Cubic feet per ton Material 100 20.0 Mine ore coming to Mill, North Star Mining Co. 100 20.0 Tailings of Mill, Calumet and Hecla Mining Co., Michigan. 100 20.0 "Blue ground" (altered peridotite) as it comes from the Kimberly mines, South Africa. 96 20.8 Broken quartz as it comes from the Jumpers' Deep mine, South Africa. 95 21.1 Broken quartz conglomerate as it conies from the Ferreira mine, South Africa. 87 23.0 Material from gravity stamps. 77 26.0 Material from gravity stamps, with the slimes removed. 75 26.6 Quartz stamped dry through 40 mesh and charged dry into vats at the "Victoria mill, Hauraki penin- sula, New Zealand. 250 MANUAL OF CYANIDATION *^ i 0 1 i I 3 | ,J S "3 | g 5 i 5 §^ Color and character "« 2 fj 3 i Tin-white, metallic, opaque. Silver-white to redish, cubic, Copper-red, malleable and dv Black. ^D * S 1* •° c -6 S II Azure-blue. Brass-yellow, brittle. Copper-red to brown, brittle Indigo-massive. Blackish lead-grey, often sectile. Flint-grey to iron-black. Greyish-black, brittle. Turquoise- blue, translucent rather sectile. -2 •"c ,0 ^ i ,0 ,C tt K Gold-yellow, malleable and d Steel-grey to silver-white to ye Pale bronze-yellow, massive. Steel-grey to iron-black, brittl< || 0 ;. 2 (N « 21 22o J CN 1 o •<? CO CM i  00 ^4 (N IQ  r O CO „ 5 CO ^ w w u ti tx Formula j i! 5 5 a '0 O O 2 CuCOs.Cu(C CuFeSt CusFeS* o o V, \ O I II 55 Cu2ClH3O3 Au (Au.Ag)Te2[Au:A (Au.Ag)Te,[Au:A (Ag.Au)2Te[Au:A Mineral Stibnite Antimony) T55 B 2 * JIM ill ill I'll Azurite lalcopyrite Bornite "3 w .. l|l \ ey-copper) Enargite hrysocolla itacamite Native ylvanite /alaverite Petzite x— S£ ^ 0 H 3 0 CO a « 5 S 03 V •** 4) « c 0 -«-» TS *O J ^ 2 •S C <u • H t> OP W Q) £ 3 02 si ~ 0 3 -s 1 1 o -f Hill ^ ^ CO CO 02 Antimon 11 J.B "3 > ,ll 1 ^ 02 02 1 ^ :• I ( 1 X! a 1 i o o o 0 TABLES 251 • III -<NrHrH WOOCOO <N K! ,X ' IN L J T « 1 WOSO-H 1 lilii o.Q)««ori --- - 13536111 Ilsa &d II 252 MANUAL OF CYAN I DAT ION 1 . •€ j 8 § s« 1 ° f 1 ^ , | | •5 & J «* "S ^" jj 5 "S | tS o I 1 g J S 1 c 13 1 Pale copper-red, metallic Brass to bronze-yellow, ca Apple-green, amorphous, Massive, filiform, malleat Silver-white, sectile. i II 5 ii i 1-s^l i Mi 11 iJBS-itSij--0^ •°. - : M 1 d rf 1 * 1 I. 1 5 1 IIII ^§ o|l^§ -3.ca| "s i t i s. i s ;HI'L- i i| n i i 1 il :* i ttHMiB -^ "s§ P 5 ^ jd » Is 5 ^ ^ 3 ° « ^ « > « ^ « « I! J 1 I !l I! Pit!!!! HI •£» ( o g T3 OB • • CO •* lO'^O iC *C »O**O*iO ^iC O s | ^' : M' «j <N « « r-o'O iJ^:^' oicJsiC v"~x C^ CO r^i. (N (N !N «<N <£>Tf<«C .<*.T}t 1C CO TJI 1C 2 t~ »C —I 00 ^ tC £" ^ ^ * ,H oo CO 00 «O COW -HiC«C -^H-t^, Tff-ivC- fc Is h. 1C <N -H • CO COC^O,? • Tj< « t>i 1C 1C <C«O t^r**^ • O • W5 •*^'coT >COO N t^ »O NO OOCOM • OS • •* COOJ^OO *rt CO M l> 1C (N O • 1C 1C t^ "3 "3 «O» «O'fit^ -»C'»C ^"COCOCO A ^, tf a « w a ,Q ic *y H "3 O °* s cc ^ 4? » » 6 S •< s E 1 Igljo •*" - ^ " oB * dS 1 - * » g3 4 4 1 |l 1 J S loil 1 1 «1 S ? 'i | 1 8 a _: pa «! H Mineral =5 1 •"£ .§ g i & | a s 2 •-§ | 2 C C Q) '5 '» » '"^ <L « <J>a> oJtJ>> >i«>a> « B j! o .tiaj >Z;ai'--E^ xi.tirS-w -g -** •- *> « <S -2 « ® lllriej 2 s: i ss*s sli a, s -g n gsg^s^i^i^f. i§fctt ^s|-s 33 SI ,5 8 Si jijf 13'fS'S 3 5-S j* ^-S§.£ S-a's^ ffica-<c;CL(P£J5Wa^ OasH^ K^HSJ a: 02 o> Composition s> r3 i iiiii •< do S3 S •< O .•§.•§ ^-SS S •§ * •§ § a §g S"2-^5.2 II- 5-l|^ll|l|l|I !§^^ Ifc-sgg ss ^a^>s^s^s5^gl Sggs 61111 3 ^ 1 3 S5 S .2 •^ .s ? § ™ ^ TABLES 253 | I 1 o 1 i *. 11 | i !§ I ; ! * I* 1H 1 1 ig 1 I 51 * M s IB 12- § * . i .•* 1 1 * i i. 1 S I •« 1 «f I if ji I- i s.g 1 f 1 I P ill 1 I >* 1 * -gS 1 | § - S^- ^|| ". & 1 ^" 1 • 8 1 3 § ^ g fc *"* I J J ^ it s 1 II g"s&Sfl- ^ ll -sil «• a- ^-j up. MMS 11 i4r.j ® -2 ^ ^" 5 > - 5 «f S •if's •!! 'S'ShiaSSfi* ^ ^^*3 ^^3^ '^^^^3 6^6tfatfwo-^tf •< T, n « °. "*. **. ^ o *? °? T ^ "^ TT^Too1^ iO »AOoJ5O»OcOINOiOiOco"b 1-1 MINERAL 1 * ^ IO CO 00 (N U5 ^ -H . 0> <N r}< CO-CO^OO |ifj .^HT}<. • -CO CO -Tf. "S sS 2 co 2 ^ s^ 2i2 I 2 jvi COM CO <N N N C<ICO CO^*N CO N TABLE 33.— GANGUE Formula 9 ^ w S 1 8 » 1 i I -S lo' I i 1 o- 3 | | 1 II P fcjJLIjjl lit 1 1 Composition S  I .8 H» a.'a fi s I sill i | | 11 i = | .2|| ll ill 1111 1 HI ill tH3 3 •? •- 3^r^r3 r3 ^"S-S'-cS d^SsS oS.rfaj II <'»6 ^6°o 6 o's^'a^s ass scs "3 1 ^ * Q. ' ' ' ..... S- a 2 :  1! 1 I 1 Hi! lli.i j i(S 1 3 aS 1 1 5 sc^« 33! § s INDEX Accumulated dam-slime, treatment, 89 " tailings, leaching prac- tice, 70 Accumulation of zinc in precipita- tion, 175 Acetates, formed by heating of solu- tions, 10, 45 in cyanide solutions, esti- mation of, 45 Acid preliminary treatment in cyani- dation of concentrate, 170 treatment clean-up tank, 202, 203 " " for "zinc shorts," 203 " " of Butters filter leaves avoided by use of special leaf, 112 Acid-sulphate of soda for treatment of zinc precipitate, 203 Adams, Huntington, method of transfer in continuous agitation, 100 Addition of cyanide during bottle agitation, 219 " water to stock solution, 124 Advantages of aluminium precipita- tion, 197 " zinc dust as a pre- cipitant, 185 Aeration, for removal of soluble sulphides in solution, 192 in bottle agitation, 216 in slime treatment, 89 of sand charges, 68 " " " Homestake practice, 61 " " " in laboratory tests, 226 " preliminary to cyanida- tion of concentrate, 170 Agitating devices for slime pulp, 89 Agitation period in slime treatment, 99 tests, 216 " " large scale, 229 Agitator tank for aluminium precipi- tation, 192 " " clean-up, 202 " " "zinc shorts," 182 wheel for bottle tests, 216 Air prejudicial to aluminium pre- cipitation, 194 " vent for leaching tanks, 67 Air-lift data, Allen, 240 " " for aeration in slime treat- ment, 89 " " " leaching tanks, 68 Akins classifier, 65 Alkali consumption tests, 218 free, effect in titration for cy- anide, 21 " in solutions, regenerative ef- 255 256 INDEX Alkali feet on zinc cyanide solu- tions, 6 protective, determination, 26 Alkaline sulphides as harmful reduc- ing agents, 5 as solvents for gold precipi- tated by graph- ite, 15 " " estimation of, 46 in aluminium pre- cipitation, 192 present simulta- neously with silver in cya- nide solution, 2 " " reaction with lead salts, 14 " " " with solu- tions from zinc precipita- tion, 175 regenerating ef- fect on zinc cy- anide solutions, 6 Allen, A. W., air-lift data, 240 " All-sliming," 73 tests, 221 Aluminate, calcium, in aluminium precipitation, 191, 198 sodium, 191 Aluminium as precipitant in cyani- dation of silver con- centrate, 171 'dust, to precipitate sil- ver in the zinc deter- mination, 31, 32 " precipitation, 189 combined with Cross e's cyanide regener- a t i o n process, 7 Aluminium precipitation effect on slime filters, 198 for arsenic- and an- timony- sil v e r ores, 168 reactions, 190 use in the desulphurizing process, 166 Alvarado Mining and Milling Com- pany's Reduction costs, 235 Amalgamation, applied to telluride gold ores, 157 in cyanide solution, 123 in lime water, 77 test for gold, 213 American Continuous Filter, 116 Ammonia distillation, for determina- tion of cyanates, 41 Ammonium formate, a product of cyanide decomposi- tion, 12 salts, formed by decom- posing cyanates with acids, 41 " in cyanide solu- tions, determin- ation of, 43 Anodes in electrolytic precipitation, 186 Antidote for cyanide poisoning, 238 Antimony and arsenic in silver ores, 190 INDEX 257 Antimony, effect on efficiency of cy- anide solutions, 8 influence of, in cyanida- tion of gold ores, 162 Antimony- and arsenic-silver ores, 166 .1 it U li it laboratory test for effect on solu- tions, 227 Antimony-lead anode in electrolytic precipitation, 189 Application of solution to leaching tanks, 67 Arsenic and antimony in silver ores, 190 " effect on efficiency of cya- nide solutions, 8 " influence of, in cyanidation of gold ore, 162 Arsenic- and antimony-silver ores, 166 n u it a it laboratory tests for effect on solu- tions, 227 Ashes from furnace, disposal of, 210 Assay conversion table, 248 " of slime residue, error in, 154 " " solutions for gold and sil- ver, 52 Atmospheric oxidation to assist the dissolution of gold and silver, 3 Atomic weights, 243 Aurocyanide, carbonyl, 15 Auropotassic cyanide, 1 Australian practice in slime treat- ment, 107 Automatic pulp sampler, 146 weighing of ore, 130 Available alklinaity of lime, 29, 218 B Barren plant solution, for laboratory tests, 228 17 Base metals, effect on efficiency of cyanide solutions, 8 Basic ferric sulphate a source of ferrocyanide formation, 13 Beauchamp, F. A., treatment of graphitic concentrate, 15 Berth elot, investigations on solubil- ity of silver in presence of potas- sium sulphide, 2 Bettel, W., hydrocyanic acid deter- mination, 25 Betty, W. K., the zinc-lead couple, 178 Bicarbonate of soda in fluxing pre- cipitate, 206 Bicarbonates, not classed as protec- tive alkali, 11 Blaisdell Excavator, for discharging sand residues, 72 Blyth, W. B., influence of arsenic in cyanidation of gold ores, 162 Bottle agitation tests, 216 Briquetting precipitate for melting, 208 Broken ore, weight of, 249 Bromide salts, for -preparation of bromocyanide, 159 Bromocyanide, as an oxidizing agent, 4 in treatment of tellu- ride gold ores, 4, 157 reaction with alkali, 158 treatment, improve- ments suggested, 161 Brown slime agitator, 91 Bucking table for wet-grinding of samples, 215 Bullion bars, sampling of, 209 Bullock, L. M. B., method of pack- ing zinc boxes, 181 Burt filter, 116 258 INDEX Butters and Mein distributor, 55 " " " " as a collector of deslimed sand, 57, 62 Butters, Charles, method of slime treatment, 88 Butters Divisadero Company, ex- periments on relative efficiency of sodium and potassium cyanides, 17 Butters Divisadero Company, prac- tice in aluminium precipitation, 195 Butters filter, drawbacks, 110 " special leaf to obviate acid treatment, 112 Butters vacuum filter, 108 Calcining zinc precipitate, 204 Calcium aluminate in aluminium precipitation, 191, 198 " carbonate on leaching tank filter cloths, 70 " zinc ate formed in solutions from zinc precipitation, 6, 176 Calculations for dissolved value loss in Dorr counter-cur- rent system, 118 of Mill heads value by difference, 152 Caldecott, W. A., error in assay of pulp containing soluble gold, 154 " " investigation in treatment of dam-slime, 89 " " " reaction of lead sulphide in cy- anide solution, 14 " " separating cone, 61, 63 Caldecott, W. A., Table, weights and volumes of slime pulp, 134 " " vacuum filter for sand, 62 Capacity of Dorr thickeners, 79, 81 " zinc boxes, 183 Capillarity effect in sand percola- tion, 69, 226 Carbonate of zinc and calcium, formed in solutions from zinc pre- cipitation, 176 Carbonic acid, a decomposer of cy- anide, 11 Carbonyl aurocyanide, 15 Carpenter, J. A., improvements in Trent agitator, 96 Cathodes in Minas Prietas electro- lytic practice, 186 " Siemens-Halske precipi- tation, 186 Caustic soda, formed in Crosse's cy- anide regeneration process, 7 " in aluminium precipi- tation, 190 " reaction on steel pre- cipitation boxes, 181 Charcoal, a precipitant of gold from cyanide solutions, 15 method of precipitation, 199 Charging crucibles with precipitate, 208 Chemical oxidizing agents, as aids to the dissolution of gold and sil- ver, 3 Chiddey-Magenau method of solu- tion assay, 53 Chloride of silver, reaction with cy- anide solution, 1 INDEX 259 Chloridizing roast for refractory manganese ores, 164 " " silver con- centrate, J69 Circles, formulas, 248 Clark, A. J., and Sharwood, W. J., Homestake slime process, 105 Clarification of solutions for precipi- tation, 173 Classifier, the Akins, 65 " Dorr, 64 " " Dorr washing, 66 Classifiers, mechanical, 63 Cleaning up the zinc boxes, 182, 202 Clean-up in charcoal precipitation, 201 Clennell, J. E., action of air on cy- anide solutions, 11 amalgamation in cyanide solution, 123 " " " determination of ammonium salts in cyanide solutions, 43 " " method of reducing iron, 38 " titrating cyanide solutions containing cop- per, 23 Clennell, J. E., on copper determin- ation, 33 " " " formation of ace- tates in cyanide solutions, 45 " " " making decinor- mal solution of iodine, 31 " " " specific gravity determination of dry ore, 132 Clennell, J. H., on " total" cyanide determination, 24 " " reactions in titration of bromocyanide, 158 Clennell, J. E., reactions in zinc pre- cipitation, 174 " " reaction of c o p p e r with cyanide solution, 12 Clennell, J. E., reaction of lead salts with silver sulphide, 14 Clennell, J. E., relative efficiency of metallic cyanides, 16 " " titration for protec- tive alkali, 27 Clevenger, G. H., agitator for bottle tests, 216 " " experiments on Nipissing silver ore, 166 " " method of pour- ing crucibles, 209 Clevenger, G. H., Young, H. W., Turner T. N., error in density de- termination of slime due to specific gravity of solution, 140 Coagulation of slime, 76 Coarse gold, 214 Coe, H. S., and Clevenger, G. H., on calculating capacity of slime thick- eners, 80 Colbath, J. S., zinc dust precipita- tion, 184 Collecting tank for sand, 55 " " " the Hamil- ton, 59 Colloidal material estimated by pan- ning, 220 Colorimetric detection of gold in cy- anide solutions, 53 ' ' estim atio n of copper, 35 260 INDEX Colorimetric estimation of iron, 37 ' silver in cyanide solutions, 54 Commercial considerations in "all- sliming," 74 Compression phase in slime thicken- ing, 80 Computation of cyanide consump- tion in laboratory tests, 222 Concentrate, cyanidation of, 169 Concentration, formulas for calcu- lating recovery, 248 tests, 227 Cone classifiers, the Merrill, 60 " the Caldecott, 61, 63 " formula for cubic capacity of, 248 Consumption of cyanide, at anode in electro- 1 y t i c precipi- tation, 189 " " by atmos- pheric oxidation, 11 Consumption of cyanide, by base metals, 12 Consumption of cyanide, by heating of solutions, 5, 10 Consumption of cyanide, by hydrol- ysis, 11 Consumption of cyanide, by me- chanical loss, 10 Consumption of cyanide, by metallic iron, 12 due to silver in laboratory tests,224 Consumption of cyanide, due to un- necessarily strong solutions, 9 Consumption of cyanide, in cyanida- tion of concen- t r a t e , 170 Consumption of cyanide in labora- t o r y tests, 222 " " *' in treating silver ores, 10 in zinc pre- c i p i ta- tion, 10 Contact period in sand leaching, 68 Continuous agitation, 99, 102 and counter- current de- cantation, 117 Conversion table, Fahrenheit to Centigrade, 242 tables, weigh ts and measures, 246 " assay weights, 248 • Copper, action in zinc precipitation, 178 " colorimetric estimation, 35 " determination in cyanide solutions, 33 " effect on efficiency of cyan- ide solutions, 8 " elimination in sulphocyan- ate determination, 40 in aluminium precipitation, 197 " charcoal precipitation, 200 " " the cyanidation of con- centrate, 171 " reaction with cyanide solu- tions, 12 " titration of cyanide solutions containing, 23 " solutions at the Minas Prie- tas plant, 186, 188 INDEX 261 Corrections for specific gravity of solution in slime pulp determina- tion (Table), 142 Costs, general reduction, for various mills (Tables), 233 " in the Denny desulphurizing treatment, 168 " of aluminium precipitation, 198 Cottrell precipitator in chloridizing roasting, 165 Counter-current decantation, Dorr system, 117 Cracks in filter cake, 108 Crawford, P. H., aluminium precipi- tation, 195 Creston Colorada, experiments on relative efficiency of sodium and potassium cyanides, 16 Critical point in addition of lead compounds to pulp, 14, 227 Crosse, A. F., process of cyanide re- generation, 7 Crowe vacuum process in zinc pre- cipitation, 174, 177 Crucible-melting of precipitate, 204 Crucible reverberatory furnace, 204 Cupellation of lead bullion in Home- stake practice, 212 Cupellation of lead bullion in the Tavener process, 211 Current density in electrolytic pre- cipitation, 186 " Minas Prietas electrolytic practice, 187 ". efficiency in electrolytic precipitation, 188 Cyanate determination, 41 formed by oxidation of cy- anide solutions, 11 Cyanates, produced by oxidizing agents, 4 Cyanidation of concentrate, 169 11 flotation concen- trate, 172 Cyanide consumption, by base met- als, 12 " mechan- i c a 1 loss, 10 computation in labora- tory tests, 222 " " excessive, in 1 abora- tory tests, 229 " in cyani- dation of concentrate, 170 Cyanide consumption, in laboratory tests due to silver, 224 Cyanide consumption, in treating silver ores, 10 Cyanide consumption, in zinc pre- cipitation, 10 Cyanide (free), determination, 20 " loss in residues, 12, 223 ' ' method of copper • determi n- ation, 34 " poisoning, antidote, 238 11 "total," determination, 24 " traces, in water, detection of, 25 " solution, effect on amalga- mation, 123 " strength in slime treat- ment, 98 D Data of cyanide tanks in various plants, 231 262 INDEX Data of slime filters in various plants (Table), 232 Dayton, Nevada, practice in pre- cipitation of coppery solutions, 179 Deoantation process of slime treat- ment, 107 " " conducive to loss of cya- nide, 10 Decomposition of cyanide solution, 10 Deep leaching tanks versus shallow ones, 69 Definition of slime, 73 Dehne filter press, 107 Denny, J. J., desulphurizing arsenic- and antimony-silver ores, 166 Denny, J. J., desulphurizing precipi- tated silver sulphide, 199 Density determination of slime pulp, 132 Depth of sand charge, 69 Devereux agitator, 96 Diamond dye, in estimating oxygen in working solutions, 51 Diaphragm cone, the Caldecott, 61, 63 " porous, used in electro- lytic precipitation, 189 Diehl, Dr., bromocyanide treatment, 157 Dilution of pulp in slime treatment, 98 Disc filter, 115 Discharging of sand residue, 72 Discrepancy between recovery and theoretical extraction, 126 Dissolving effect of zinc potassium cyanide, 5 efficiency of sodium and potassium cyanides, 15 Distributor, Butters and Mein, 55, • 61, 62 Divisadero Mill special filter leaf, 111, 198 Dorr, J. V. N., classifier, 64 Dorr continuous counter- current de- cantation, 117 Dorr continuous counter-current de- cantation in aluminium precipita- tion, 198 Dorr slime agitator, 93 " " thickener, 79 " thickeners, operation of, 86 " washing classifier, 66 Double filtering, 124 "Double salt" potassium cyanide, 15, 17 Double treatment for sand, 60 Dowsett, C. W., colorimetric detec- tion of gold in cyanide solutions, 53 Draining dry between washes, 68 Dressing the zinc boxes, 181 Dropping the cakes in the Butters filter, 108 Drucker, A. E., reduction of matte, 210 Dry ore, specific gravity determina- tion, 132 Drying of samples before cyanida- tion to be avoided, 214, 216 " " zinc precipitate for melt- ing, 204 Dry-screening in laboratory tests, 220 Durant, H. T., aeration of dam- slime, 89 u it u modification in elec- trolytic precipita- tion, 186 Dyscrasite, in Nipissing silver ores, 166, 168 INDEX 263 E Edmands, H. R., method of charcoal dust precipitation, 199 Efficiency of a cyanide solution pro- portional to free cy- anide as determined without KI indica- tor, 6 " " slime niters in alu- minium precipitation, 198 El Oro, Mexico, air-lift for leaching tanks, 68 Electrolysis of solutions in acid treat- ment of manganese-silver ores, 165 Electrolytes in slime settlement, 76 Electrolytic precipitation, 185 " " for dealing with coppery s o lu - tio ns, 179 Eisner's equation, 1 Error in density determination due to specific gravity of the solution, 140 Evaporation in laboratory bottle tests, 217 of solution in leaching tests, 226 Excess of bullion over calculated amount, 127, 156 Experiments, 213 Extraction determination in labora- tory tests, 224 Extractor, Moore-Edmands, for charcoal precipitation, 200 Feldtmann, W. R., on treatment of graphitic ores, 15 Ferric sulphate, basic, a source of ferrocyanide formation, 13 Ferric sulphocyanate, 40 Ferricyanide, as an oxidizing agent, 3 Ferrocyanide determination, 36 " in cyanidation of con- centrate, 170 Ferrocyanides, formation in cyanide solutions, 12 not detrimental re- ducers, 4 Ferrous compounds, formed in slime dams, 4 " in treatment of concentrate, 170 Ferrous hydroxide, formed in Sie- mens-Halske precipitation, 186 " reaction with cy- anide solu- tions, 13 Ferrous salts, in cyanidation of ar- senical gold ores, 162 " sulphate, as a harmful re- ducing agent, 5 " " in slime dams, 89 " sulphide, as a harmful re- ducing agent, 5 " in slime dams, 89 Filter, the Caldecott, for sand, 62 Filter-bottom construction for leach- ing tanks, 66 Filter-cake sampling, 153 Filter-press, the Dehne, 107 " " Merrill, 105 Filter-presses, in treatment of slime, 102 Filters or clarification of solutions, 173 •' vacuum, in treatment of slime, 107 264 INDEX Fine crushing of mill head samples, importance of, 149 Fine grinding, 73 " for coarse gold, 214 in cyanidation of con- centrate, 170 of silver ores, 75 Fine sand leaching, 74 Fineness of grinding, test for, 218 Fixation of gold in slime pulp, 154 Flotation concentrate, cyanidation of, 172 of manganese-silver ores, 165 process for treatment of graphitic ores, 15 Flow sheet of a Mexican mill, 237 Fluxing the precipitate, 205 Formates, formed by heating of solu- tions, 10 in cyanide solutions, esti- mation of, 43 Formulas, weights and volumes of slime pulp for ores of varying specific gravity based on the short ton, 137 " weights and volumes of slime pulp for ores of varying specific gravity based on the metric ton, 139 Fouling of solutions, 8, 168, 190 " laboratory test, 227 suggested rem- edy, 7 Free cyanide determination, 20 "Free" settlement of slime, 80 Gold, assay of solutions for, 52 ' ' in alumi nium prec ipitatio n, 1 97 Gold, in cyanide solutions, colori- metric detection of, 53 " ores, low grade, and zinc dust precipitation, 184 " reaction with cyanide solu- tion, 1 Graphite, in cyanidation of gold ores, 162 Graphitic ores, causing premature precipitation, 15 Gravity percolation in leaching, 67 Green, Leonard M., titration for protective alkali, 29 Grinding in the laboratory com- pared with mill work, 222 laboratory samples in tube mill, 13 of samples, wet, 214 samples to a given screen size, 222 tests for necessary fineness, 218 II Hahn, A. A., use of manganese dioxide in melting precipitate, 206 Julian, H. F., aluminium precipita- tion, 189 Julian, H. F., and Smart, K, action of bromocyanide, 4 Julian, H. F., and Smart, E., action of weak solutions, 9 Julian, H. F., and Smart, E., bromo- cyanide treatment, 157 Julian, H. F., and Smart, E., depolar- izing action of oxygen, 3 Julian, H. F., and Smart, E., dilution of pulp in slime treatment, 98 Julian, H. F., and Smart, E., effect of copper on efficiency of cyanide solutions, 8 Julian, H. F., and Smart, E., effect, of temperature on rate of dissolution of gold, 5 Julian, H. F., and Smart, E., flux for precipitate, 206 Julian, H. F., and Smart, E., forma- tion of acetates in cyanide solu- tions, 45 Julian, H. F., and Smart, E., percola- tion of sand, 69 Julian, H. F., and Smart, E. , reaction in zinc precipitation, 174 Julian, H. F., and Smart, E., reaction of copper with cyanide solutions, 12 Julian, H. F., and Smart, E., washing out the dissolved metals in leach- ing treatment, 71 Julian, H. F., and Smart, E., zinc- lead couple, 178 K Kalgurli, air-lift for leaching tanks, 68 practice for telluride ores, 157 Kelly filter, 116 Kirkpatrick, S. F., aluminium pre- cipitation, 189 Kline, R. C., increased extraction due to presence of potassium base, 18 " " " treatment of silver matte, 210 Laboratory experiments, 213 Large scale agitation tests, 229 " sand leaching tests, 226 Layng, H. R., dissolving silver sul- phide in cyanide solution, 3 Leaching of fine sand, 60, 74 " raw concentrate, 169 " sand, 55 tank construction, 66 tests, 224 " on sand by agitation method, 219 " " preparation for, of easily oxidized ores, 225 treatment procedure, 66 Lead compounds, as a prevention of sulphocyanate formation, 14 as aid to extrac- tion of silver ores, 14 effect on efficiency of cyanide solu- tions, 8 " in laboratory tests, 227 INDEX 267 Lead compounds, use of, prejudicial with antimony- and arsenic-sil- ver ores, 192 " peroxidized, as anodes, 187 " sulphide, reaction with cyanide solutions, 14 Leaf, special, for Butters niters, to obviate acid treatment, 112, 198 Leaver, E. S., amalgamation in cy- anide solution, 123 Leslie, H. M., experiments on loss of cyanide as HCN, 11 Lime, a regenerator of cyanide from double zinc salt, 6, 224 " addition in milling, 76 " amount added in milling, 77 " available alkalinity of, 29, 218 " carbonate on leaching tank filter cloth, 70 " consumption tests, 218 " elimination by soda ash in aluminium precipitation, 195 in aluminium precipitation, 191 " reaction with solutions from zinc precipitation, 175 Lime-water in amalgamation, 77 Litharge, a substitute for lead ace- tate in treating silver ores, 14 in the Homestake melting practice, 211 " " " Tavener melting process, 210 Loss of cyanide in residues, 10, 223 Lowering vacuum to prevent forma- tion of cracks in filter cake, 108 M Mac Arthur, J. S., zinc-lead couple, 178 Mac Donald, Bernard, the Parral tank, 96 Manganese-silver ores, 163 Marcasite, a source of ferrocyanide formation, 13 Matte, reduction of, 210 Mechanical agitator for slime pulp,89 " classifiers, 63 " indirect treatment of sand, 65 Melting gold precipitate from char- coal precipitation, 201 the precipitate, 204 Merrill, C. W., cones, 60 " " " sand collection, 60 " " " slime press, 105 " " " triangular precipita- tion press, 184 " " " zinc dust precipita- tion, 183 Metallic gold and silver in labora- tory experiments, 213 Metals and their minerals (Table), 250 Methyl orange, as indicator in pro- tective alkali determination, 11 Metric weights and measures, 245 Mexican reverberatory melting prac- tice, 205 Middling in concentration, elimina- tion by calculation, 249 Mill head sampling, 146 Milling in cyanide solution, 123 " " solution, sampling of head, 148, 155 " water, 77 Minas Prietas practice in electro- lytic precipitation, 186 Minerals, and their characteristics (Tables), 250 Mispickel gold ores, treatment of, 4, 157 268 INDEX Mixing the fluxes for melting pre- cipitate, 208 Moisture determination as a substi- tute for specific gravity of slime pulp, 141 estimation in mill ore, 130 retained in sand charge, 69 Moldenhauer, aluminium precipita- tion, 189 Moore, vacuum filter, 112 X Nardin, E. W., details of bromocya- nide treatment at Hannan's Star Mill, 158 Neal, Walter, flux for silver precipi- tate, 207 " treatment of mangan- ese-silver ores, 165 Neutral solutions for treating anti- monial gold ores, 162 "Nigger and hose" system of slime separation, 57 Nipissing mill melting practice, 205 practice, aluminium pre- cipitation, 190 " "in sodium sul- phide precipi- tation, 199 reduction costs, 235 silver ores, treatment of, 166 Nitre, in melting precipitate, 206 Nitric acid, decinormal solution, 26 Nutter, E. H., amalgamation in cyanide solution, 123 0 Oliver vacuum filter, 112 Ore, broken, weight of, 249 " head sampling, 146 Organic matter, as a harmful reduc- ing agent, 5 Over-grinding of samples, 222 in tube mill.,214 Oxalic acid, decinormal solution, 26 " for titr ation of protective alkali, 26 " standard solutions, 28 table of varying strength and factors, 29 Oxidation, as a remedy for fouling of solutions, 8 " an aid to treatment of antimonial gold ores, 162 of cyanide solutions, 11 " soluble sulphides, 1 " zinc during the clean- up, 182 Oxidizing agents as aids to the dis- solution of gold and silver, 3 " in melting precipi- tate, 206 " roast detrimental to silver ores, 164 " of silver concentrate detrimental to cy- anide treatment, 169 Oxygen, action of, in zinc precipita- tion, 176 as a depolarizing agent, 3 dissolved in distilled water, 50 estimation of, in working cyanide solutions, 48, 176 function in dissolving gold and silver, 3 rapidly absorbed by current solutions, 177 Ozone, as an oxidizing agent, 3 INDEX 269 Pachuca agitation a source of cy- anide loss, 11 cyanide strengths used, 9, 98 practice in zinc dust pre- cipitation, 174, 185 " slime agitator, 91 tanks, dilution of pulp, 99 " in the laboratory, 217 Paper bags for charging crucibles, 208 Park, James, action of copper in zinc precipitation, 179 '' charcoal precipitation, 199 " definition of slime, 73 " fluxes for precipitate, 206 " process of slime treat- ment, 106 " reactions in zinc pre- cipitation, 174 Parral agitator tank, 96 Percolation rate, 69 Percolator for leaching tests, 225 Permanganate, as an oxidizing agent, 3 decinormal solution, 38 estimation of reduc- ing agents, 4 to check action of cyanide in pulp samples, 154 Peroxide of sodium, as an oxidizing agent, 3 Peroxidized lead anodes, 187 Phenolphthalein, as indicator in pro- tective alkali determination, 11, 27 Piping for leaching tanks, 67 Plant data, cyanide tanks, 231 Poisoning by cyanide, antidote, 238 Potassium and sodium cyanides, rel- ative dissolving effi- ciency, 15 cyanide, as the standard for titration, 19 ferricyanide, as an oxi- dizing agent, 3 iodide, indicator in cy- anide titration, 21, 23, 24 permanganate, as an oxi- dizing agent, 3 decinor- m a 1 solu- tion, 38 salts, conducive to in- creasing extraction, 18 Pouring crucibles, 209 Power data, 249 Precious metals as a source of cy- anide consumption, 9 Precipitate obtained from alumin- ium precipitation, 197 Precipitating action of antimony and pyrrhotite in cyanidation of gold ores, 162 Precipitation by zinc, a source of cy- anide loss, 10 of the gold and silver, 173 premature, 14 Preparation of precipitate charge for melting, 208 Press for zinc dust precipitation, 184 Pressure data, 249 Protective alkali, definition of, 26 determination. 26 270 INDEX Prussian blue, formed in Siemens- Halske precipita- tion, 186 " in sulphocyanate de- termination, 40 Pulp sampler, automatic, 146 Pyrite, a source of f errocyanide for- mation, 13 Pyrogallic acid, use in estimating oxygen in working solutions, 48 Pyirhotite, in cyanidation of gold ores, 162 Q Quantity of solution in leaching treatment, 70 R Rand, experiments on loss of cy- anide as HCN, 11 " institution of double treat- ment for sand, 60 " practice in slime treatment, 107 " strength of solution in slime treatment, 98 Rate of percolation, 69 Ratio of aluminium to silver in aluminium precipita- tion, 190 " " solution to ore in leaching treatment, 70 " " zinc to silver in zinc pre- cipitation, 174 Reactions in zinc precipitation, 174 Recovery, discrepancy with theoret- ical extraction, 126 in concentration, formu- las, 248 Reducing action of accumulated dam-slime, 89 Reducing agents, 4, 8 " " formed in slime dams, 5 power, estimation of, 4 treatment an aid in cyan- iding refractory man- ganese-silver ores, 164 Reduction costs for various mills (Tables), 233 method of determining iron, 38 of slime filter efficiency in aluminium precipita- tion, 198 Refining silver bullion at Nipissing, 205 Regeneration of cyanide by acid treatment, 8 Regeneration of cyanide by Crosse's process, 7 Regeneration of cyanide from the double zinc salt, 6, 224 Regeneration of cyanide from zinc cyanide solutions, 10 Regeneration of cyanide in alumin- ium precipitation, 171, 190, 197 Regeneration of cyanide in electro- lytic precipitation, 188 Regeneration of cyanide in sodium sulphide precipitation, 171, 199 Relative dissolving efficiency of so- dium and potassium cyanides, 15 Repeated use of solutions, labora- tory test, 227 Residue, loss of cyanide in, 10, 223 sampling, 152 " sand, discharging, 72 Retained moisture in sand charge, 69 Reverberatory for bulk melting of precipitate, 205 " melting, Homestake practice, 211 INDEX 271 Reverberatory melting, Tavener process, 210 Roasting for telluride gold ores, 157 " of gold concentrate, 169 Roscoe & Lunt, table showing oxy- gen dissolved in distilled water, 49 S Sampler for pulp, automatic, 146 Sampling bullion bars, 209 " by hand, mill heads, 149 " of mill heads, 146 " " " when mill- ing in so- lu t ion, 123, 148, 155 " residues, 152 " plant, for mill heads, 148 pulp at different stages of treatment, 153 Sand filter for clarification of solu- tions, 173 " in "all-sliming" product, 74 " " melting precipitate, 205 " leaching, 55 strength of solutions, 9 tests, large scale, 226 " residues, discharging, 72 sampling, 152 ' ' tonnage, comp utation by meas- urement, 128, 131 Santa Gertrudis experiments in elec- trolytic precipitation, 189 Saving by aluminium precipitation, 197 Screen sizing, in water, 220 " tests, 219 " on pulp before cyanidation, 221 Screening out "zinc shorts," 203 " samples wet, 215 Selective action of weak solution, 8 " agitation in the Dorr tank, 95 Separation of sand and slime, 55 by dry screening, 225 by washing in the laboratory, 225 Settlement of slime, 76 Sharwood, W. J., estimation of sul- phocyanate, 40 " " on copper deter- mination, 34 " " " solubility of sil- ver in pres- ence of po- tassium sul- phide, 2 Short zinc, 182, 203, 207, 211 Shortage of bullion in clean-up, 126 Short-circuiting of pulp in continu- ous agitation, 100 Siemens-Halske electrolytic precipi- tation, 178, 185 Sieves, I. M. M. London standard, 240 " Tyler Standard, 238 Silver, a source of cyanide consump- tion in cyanidation of con- centrate, 171 " as a source of cyanide con- sumption, 9 " assay of solutions for, 52 " chloride, reaction with cy- anide solution, 1 " determination, Volhard's method, 44 " in charcoal precipitation, 200 " " cyanide solutions, colon- metric estimation of, 54 " metallic, reaction with cy- anide solution, 1 272 INDEX Silver, nitrate, decinormal solution, 44 " standard solution, 20 standard solution, table of varying strengths and fac- tors, 25 " ores containing arsenic and antimony, 166 " fine grinding of, 75 " sulphide, causing formation of sulphocyanate, 13 " " not acted on by zinc-potassiu m cyanide, 5 precipitate, reduc- tion by Denny's process, 199 " precipitated from cyanide solution by diluting with water, 2 " reactionwith cyanide solutions, 1,2,9 Silver sulphide, reaction with lead salts, 14 Silver sulphide, solubility in cy- anide solution in presence of sodium sulphide, 2 sulphocyanate, 3 Silver-manganese ores, 163 Sizing tests, 219 Slag, disposal of, 209 Slime, coagulation of, 76 " definition of, 73 " filters in various plants (Table), 232 " in laboratory tests estimated by panning, 220 residue, loss of cyanide in, 10 sampling, 153 Slime, retarding action in percola- tion of sand, 69 " separation from sand, 55 " in the laboratory by washing, 225 " settlement, 76, 80 " spitzkasten, 77 " the extraction treatment, 88 " thickening tank, 79 " tonnage estimation by specific gravity, 131 " treatment in filter presses, 102 strength of solu- tions, 9 Sluicing out sand residues, 72 Snifter valve, for aeration in slime treatment, 89 Soda ash, use in aluminium precipi- tation, 195 " caustic, formed in Crosse's cy- anide regeneration process, 7 Sodium aluminate, 191 " cyanide, 16 peroxide, as an o x i d i z i n jr agent, 3 " and potassium cyanides, rel- ative dissolving efficiency, 15 " (potassium) sulphate, formed by oxidation of sodium sulphide, 1 " sulphide, as precipitant in cyanidation of silver con- centrate, 171 " (potassium) sulphide, formed in dissolving silver sulphide, 1 sulphide, in Crosse's cy- anide regenera- tion process, 7 " method of precipi- tation, 199 INDEX 273 Sodium, (potassium) sulphocyanate, formed by reaction of cy- anide with silver sulphide, 1 " thiosulphate, decinormal solution, 31 " (potassium) thiosulphate, formed by oxidation of sodium sulphide, 1 Soluble sulphides, as harmful reduc- ing agents, 5 estimation of, 46 " " in aluminium pre- cipitation, 192 " " present simultane- ously with sil- ver in cyanide solution, 2 " reaction with lead salts, 14 Soluble sulphides, reaction with solu- tions from zinc precipitation, 175 Soluble sulphides, regenerating effect on zinc cyanide solutions, 6 Solution, application to leaching tanks, 67 ratio ' in leaching treat- ment, 70 strength in cyanide, 8, 9 • " " " leaching treat- ment, 70 Sources of apparent shortage of bul- lion, 128 " " cyanide consumption, 9 Special filter leaf for Butters filter, 111, 198 Specific gravity of dry ore, deter- mination, 132 " " solution, a source of error in slime density determination, 140 18 Specific gravity of wet pulp, deter- mination, 133 " to estimate tonnage of slime pulp, 128, 131 Spitzkasten for slime, 77 Stages of treatment, sampling of pulp, 153 Standard solutions of oxalic acid, 28 Standard solutions of oxalic acid, table of varying strengths and factors, 29 Standard solutions of silver nitrate, 20 Standard solutions of silver nitrate, table of varying strengths and factors, 25 Standardization of decinormal per- manganate, 39 " sodium sulphide solution, 47 Steel precipitation boxes, reaction with caustic soda in solutions, 181 Strength of cyanide in slime treat- ment, 98 " " solution in cyanide, 8, 9 "leaching treatment, 70 Strong solution, making up for the leaching treatment, 70 Succession of washes, for increasing the dissolving effect, 99, 121 Sulman, H. L. & Picard, H. K., zinc dust precipitation, 183 Sulphantimonide silver ore, 166 Sulpharsenide silver ore, 166 Sulphates of iron, in the cyanidation of concentrate, 170 " sodium formed by oxi- dation of sodium sul- phide, 1 274 INDEX Sulphide of silver, not acted on by zinc potassium cyanide, 5 " " " reaction with cy- anide solu- tion, 1 " sodium, in aluminium pre- cipitation, 192 " in Crosse's cyanide regeneration process, 7 " method of precipi- tation, 199 Sulphides, soluble, as harmful reduc- ing agents, 5 " " estimation of, 46 " formed in dis- solving silver sulphide, 1 Sulphocyanate, a source of cyanide consumption, 13 decinormal solution, 44 determination, 39 " formed by reaction of cyanide with silver sulphide, 1, 13 from lead sulphide, 14 " " in the treat- m ent of silver ores, 9 in aluminium pre- cipitation, 192 method of estimat- ing iron, 37 not a detrimental reducing agent, 4 % " of silver, 3 Sulphuretted hydrogen, as a harmful reducing agent, 5 i n d a m - slimes, 89 44 " u s e d i n Crosse's cyanide regenera- tion proc- ess, 7 Sulphuric acid treatment in the cy- anidation of concentrate, 170 Sulphurous acid, as a harmful reduc- ing agent, 5 " " determination, 166 " treatment of man- ganese-silver ores, 165 Sutton (Vol. Anal.), saturating dis- tilled water with oxygen, 49 Sweetland filter, 116 Tank capacities, formula, 248 Tavener, P. S., process of melting precipitate, 210 Telluride gold ores, 157 " " " treatment of, 4 Temperature of solutions, effect on rate of dissolution of gold, 5 Thermometer conversion table, 242 Thickener, the Dorr, 79 Thickening of slime pulp, 77, 80 Thiosulphate, as a harmful reducing ing agent, 5 for titration of bromo- cyanide, 158 " formed by oxidation of sodium sulphide, 1 INDEX 275 Thiosulphate, in aluminium precipi- tation, 192 of soda, decinormal solution, 31 " solution, standardiza- tion with copper sulphate, 159 Time of agitation in slime treatment, 99 Tin plate, as cathodes, 187 Tonnage computation, 127, 130 Tonopah Belmont, reduction costs, 234 Tonopah practice, in heating of solu- tions, 5 "Total" cyanide determination, 24 Traces of cyanide in water, detection of, 25 Trent agitator, 95 Tube mill for laboratory samples, 214 " " grinding of laboratory samples, 13 Tyler standard sieves, 219, 238 U Upward percolation in leaching, 67 Vacuum application in sand leach- ing, 70 filter for sand, the Calde- cott, 62 filters, 107 " use in sand leaching tests, 226 Vent for air entrapped in leaching tanks, 67 Virgoe, Walter, elimination of zinc in solutions from zinc precipitation, 176 Virgoe, Walter, method of solution assay, 52 " titration of cyanide solutions contain- ing copper, 23 Volatilization in chloridizing roast- ing, 164 Volhard's silver determination, 44 Volume of solution, ratio to alumin- ium in aluminium precipitation, 191 W Waihi Grand Junction, reduction costs, 234 Washes, a succession of, for increas- ing the dissolving effect, 99, 121 Washing out the dissolved metals after slime treatment, 106 Washing out the dissolved metals in the leaching treatment, 71 Water, addition of, to stock solu- tion, 124 " to replace solution in zinc box clean-up, 202, 203 " wash, effect in increasing ap- parent dissolving action in pulp, 121 Weak solutions, precipitation of, 178 selective action, 8 Weights and measures, conversion tables, 246 English and American, 244 metric sys- tem, 245 Wet-grinding of samples, 214 on buck- ing table, 215 Wet pulp, specific gravity determina- tion, 133 276 INDEX Wheeler, Roscoe, data on the Dever- eux agitator, 96 Whitby, A., assay of slime pulp con- taining soluble gold, 155 White end-point in titration for free cyanide, 22 White, H. for coppery solutions, 179 " effect in titration for free cy- anide, 21 " " on efficiency of cyanide solutions, 8 11 ferrocyanide in the white pre- " cipitate, 176 *' hydroxide, in the white precipi- tate, 176 " in the cyanidation of concen- trate, 171 " -lead couple, 178, 186 " plant solution for laboratory tests, 228 " -potassium cyanide, dissolving effect, 5 " precipitation, a source of cy- anide loss, 10 " " detrimental in treatment o f arsenic- and antimony-silver ores, 168, 190 reactions, 174 " shavings, dimensions preferred, 181 " shaving precipitation, a source " of apparent shortage of bul- lion, 128 "Zinc shorts," 182, 203 " " melting at Dos Es- t r e 1 1 a s mill, 207 INDEX 277 "Zinc shorts," melting by the Tave- Zincate, alkaline, formed in zinc cy- ner proc- anide solutions, 6 ess, 211 " calcium, formed in solutions Zinc, standard solution for estimat- from zinc precipitation, ing soluble sulphides, 47 176 THIS BOOK IS DUE ON THE LAST DATE STAMPED BELOW HOME USE CIRCULATION DEPARTMENT MAIN LIBRARY This book is due on the last date stamped below. 1 -month loans may be renewed by calling 642-3405. 6-month loans may be recharged by bringing books to Circulation Desk. 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