example between 800 u00b0 c and 1000 u00b0 c the said heat treatment step at no higher than 1200 u00b0 c allows the refractory composition to set harden and dry such that essentially no more water is contained in said composition the obtained monolithic refractory composition then may form a refractory lining which has refractory properties but which may not yet provide improved physical properties caused by a presence of silicon carbide whiskers the advantage of the monolithic refractory composition so obtained is that it may serve as a u201c starting material u201d for providing a reinforced monolitihic refractory composition containing silicon carbide whiskers silicon carbide whiskers are formed within the monolithic refractory composition during a second heat treatment step during which the installed monolithic refractory composition after the first heat treatment undergoes a further second heat treatment at a temperature which is higher than the first heat treatment temperature under non inert atmospheric conditions such as under a normal air atmosphere during said second heat treatment step which may be carried out at the same time as normal use of the metallurgical vessel i e wherein some or all of the heat for heat treatment is provided by the presence of a molten metal in contact with said monolithic material silicon carbide whiskers are formed within said monolithic refractory composition.