0 09 mm all other test conditions were left unchanged column 1 gives the admissible eluate values of the drinking water regulations of 1986 german standards column 2 gives the admissible eluate values of dump class 2 german standards column 4 gives the eluate values of the products made in accordance with example 2 table______________________________________ i iii drinking ii dust with iv water dump class low cao finished regulations 2 content product______________________________________ph 6 5 9 5 5 5 12 0 12 4 10 7pb mg l 0 04 0 5 74 0 02hg mg l 0 001 0 005 lt 0 0002 0 0008cd mg l 0 005 0 05 lt 0 0005 lt 0 0005tl mg l 0 1 lt 0 01 lt 0 01zn mg l 5 0 4 0 lt 0 05sn mg l 0 5 0 01 lt 0 01ni mg l 0 05 0 5 lt 0 005 lt 0 005cr tot mg l 0 05 1 0 lt 0 09 0 07ba mg l 1 0 0 09 0 09strength of spot n 1 020______________________________________ this sample shows that by the addition of a mixture of cement and silica flour the excessive lime in the dust is bonded by the hydrothermal process the ph value of the finished product is within the optimum range and accordingly a low solubility of all heavy metals is recorded the cement used in example 1 was replaced by 15 parts by weight of hydrated lime all other test conditions were left unchanged the spot strength was measured immediately after compaction 34 green 34.