CN1033974A

CN1033974A - From the silicon carbide-containing slag, extract the method for silicon carbide

Info

Publication number: CN1033974A
Application number: CN 88107783
Authority: CN
Inventors: 贾阮
Original assignee: Individual
Current assignee: Individual
Priority date: 1988-11-10
Filing date: 1988-11-10
Publication date: 1989-07-19

Abstract

A kind of method of from contain the SiC slag, extracting silicon carbide, with diluted acid and (or) dilute alkaline soln removes impurity such as Mg, Ca, Fe, Si, clean, dehydration, drying obtain SiC content at the product more than 97%.The SiC that this method is extracted satisfies the requirement of industrial SiC, can make refractory materials or abrasive material.

Description

From the silicon carbide-containing slag, extract the method for silicon carbide

The invention belongs to a kind of method of from contain the SiC slag, extracting industrial silicon carbide.

The production method of known silicon carbide, as 58 pages of " refractory materials " magazine 1988 the 3rd phases, be entitled as " production method of industrial silicon carbide ", be to smelt in resistance furnace with silicon oxide and coke to form, the silicon carbide of Sheng Chaning in this way, its reaction is inhomogeneous, will go out silicon carbide products by assortment from unreacted material when coming out of the stove, and is time-consuming.Unreacted material after the selection and silicon oxide need melt down repeatedly once more to be smelted, and has both consumed a large amount of energy, and the product yield is also lower.

All contain silicon carbide (SiC content about 20～60%) in various degree in the industrial slags such as known calcium carbide, graphite, industrial silicon, these slags are all abandoned when prepurging in the field, wilderness, and both contaminate environment was again a kind of waste.

The objective of the invention is: a kind of method of extracting silicon carbide from contain the SiC slag is provided.

The object of the present invention is achieved like this: with 5～10%(weight %) dilute acid soln and (or) 20～50%(weight %) dilute alkaline soln are molten removes Mg, Ca, impurity such as Fe, Si in the slag, clean free acid (or alkali) and soluble inorganic salt class with clear water then, obtain the SiC finished product through dehydration, drying.Then need further magnetic separation and sizing screening if extract the SiC that does abrasive material.

Advantage of the present invention and positively effect are: with simple technology, lower cost, extract from the depleted slag and be worth higher carbofrax material.Compare saving of work and time with known SiC production method, save energy greatly reduces the production cost of SiC.But the quality of SiC can reach the requirement of industrial silicon carbide fully, and its concrete analysis data are as follows:

Embodiments of the invention are as follows:

Example 1: the granulated carbide slag is washed repeatedly with clear water, remove the Ca(OH that floats in the water) ₂And CaCO ₃, then at 5～10%(weight %) dilute hydrochloric acid solution in boiled 2～3 hours, molten remove impurity such as Mg, Ca, Fe after, clean free acid and soluble inorganic salt class with clear water, dewater, be drying to obtain the SiC finished product.

Example 2: the graphite furnace ground-slag is broken into the particle that diameter is 2～3mm, adds 20～30%(weight %) NaOH solution boiled 4～5 hours, molten remove impurity such as Si after, wash free alkali, dehydration, drying obtains the SiC product.

Example 3: the industrial silicon furnace ground-slag is broken into the particle that diameter is 2～3mm, adds 40～50%(weight %) NaOH solution boiled 5～7 hours, washed free alkali, and dehydration, drying obtain the SiC product.

Claims

1, a kind of method of from contain the Sic slag, extracting silicon carbide, it is characterized in that: with 5～10% (weight %) dilute acid soln and (or) 20～50% (weight %) dilute alkaline soln is molten removes Mg, Ca, impurity such as Fe, Si in the slag, clean free acid (or alkali) and soluble inorganic salt class with clear water then, through dehydration, drying.

2, by the method for the described extraction silicon carbide of claim 1, it is characterized in that: after the granulated carbide slag is washed repeatedly with clear water, at 5～10%(weight %) dilute hydrochloric acid solution in boiled 2～3 hours, clean, dry.

3, by the method for the described extraction silicon carbide of claim 1, it is characterized in that: the graphite furnace ground-slag is broken into the particle that diameter is 2～3mm, adds 20～30%(weight %) NaOH solution boiled 4～5 hours, cleans, dry.

4, by the method for the described extraction silicon carbide of claim 1, it is characterized in that: the industrial silicon furnace ground-slag is broken into the particle that diameter is 2～3mm, adds 40～50%(weight %) NaOH solution boiled 5～7 hours, cleans, dry.