Abstract: <FONT face=Verdana>A process route that reclaiming silicon carbide from drained slurry generated by cutting silicon crystal with wire-saw and simultaneously using its recovery solution to prepare white carbon black was introduced.Silicon carbide was reclaimedfirstly by high-concentration alkali-soluble method to dissolve silicon in drained slurry,and then white carbon black was prepared by hydrochloric acid replacing sulfuric acid and sodium chloride to promote salting-out and by n-butanol to control particle growth and agglomeration.Reaction between sodium hydroxide and silicon in drained slurry and acidizingreaction of water glass were studied.Results showed that the optimum conditions for the two reactions respectively were as follows:mass concentration of sodium hydroxide was 0.25~0.35 g/mL and temperature was about 55 ℃;mass fraction of sodium silicate was 9%~12%,mass fraction of hydrochloric acid was 20%~25%,n-butanol was 13 drops（approximately0.6 mL）,and temperature was about 80 ℃.Technology realized the reasonable utilization of silicon in drained slurry. </FONT>