Production method of stainless steel dusting ash pellets

Abstract

A production method of stainless steel dusting ash pellets comprises the following steps: (1) compounding and ball milling, wherein stainless steel dusting ash, coke powder and sodium silicate are added into a ball mill for mixing to be milled to mixed powder according to the mass ratio of 8-9 to 0.5-1.5) to 0.4-0.6, the granularity of the mixed powder is less than or equal to 0.6 mm, and the particle size of the mixed powder is less than or equal to 200 meshes, and the particle mass ratio of the mixed powder is greater than or equal to 65 percent; (2) binding agent preparation, wherein firstly polyvinyl alcohol is disposed to an aqueous solution with the concentration of 8-12 percent, then meerschaum is added into the polyvinyl alcohol aqueous solution with the mass ratio of the polyvinyl alcohol aqueous solution to the meerschaum of 8-9 to 2-1, and by stirring, the meerschaum is evenly suspended in the polyvinyl alcohol aqueous solution; (3) ball pressing, wherein the mixed powder and the binding agent are added into a kollermill for mixed milling according to the mass ratio of 8.5-9 to 1-1.5, and added into a pair-roller ball press machine to be made to 30-40 mm pellets after being mixed evenly by milling; and (4), pellet drying, wherein the pellets are placed into a hot-air drying furnace to be dried in hot air at the temperature of 200-220 DEG C to enable moisture to be less than or equal to 2 percent.

Description

technical field [0001] The invention relates to metallurgy, the technique of agglomerating iron and steel metallurgical powder. Background technique [0002] During the stainless steel production process, the stainless steel dust removal ash produced by the dust removal system is 30-40 Kg / ton of steel. Chemical analysis shows that stainless steel dust contains a certain amount of valuable metal elements such as nickel, chromium and iron. The average content is: Ni-2%, Cr-10%, Tfe-30%. If it is not recycled, it will not only pollute the environment , and cause waste of chromium, nickel precious metal element resources. At present, the main recycling method is to directly spray the stainless steel dust into the smelting furnace for recycling (such as the Japanese STAR furnace), or press the stainless steel dust into pellets, and use the submerged arc furnace to produce nickel-chromium pig iron to recover the nickel. , chromium and iron (such as the Befesa Valera process in F...

AI Technical Summary

Problems solved by technology

In order to ensure that the stainless steel dust-removing ash pellets reach the strength required for submerged arc furnace smelting, cement is usually used as a binder for stainless steel dust-removing ash pellets, and the addition amount is 10-20%, resulting in nickel, The comprehensive metal content of chromium and iron decreases, resulting in an increase in the amount of slag in the submerged arc furnace and an increase in the coke ratio, thereby increasing the recovery cost

Also, because the cement contains a certain amount of free CaO, it not only causes fluctuations in the compressive strength of the stainless steel dust-removing ash pellets, but also makes the gas permeability worse during the smelting process of the submerged arc furnace, the production capacity decreases, and the natural alkalinity of the smelting slag (C / S) is raised to more than 2. In order to ensure good fluidity of the slag, it is necessary to add auxiliary materials to adjust the alkalinity of the slag, further increasing the production cost