Processes for producing low nitrogen, essentially nitride-free chromium or chromium plus niobium-containing nickel-based alloys include charging elements or compounds which do not dissolve appreciable amounts of nitrogen in the molten state to a refractory crucible within a vacuum induction furnace, melting said elements or compounds therein under reduced pressure, and effecting heterogeneous carbon-based bubble nucleation in a controlled manner. The processes also include, upon cessation of bubble formation, adding low nitrogen chromium or a low nitrogen chromium-containing master alloy with a nitrogen content of below 10 ppm to the melt, melting and distributing said added chromium or chromium-containing master alloy throughout the melt, bringing the resulting combined melt to a temperature and surrounding pressure to permit tapping, and tapping the resulting melt, directly or indirectly, to a metallic mold and allowing the melt to solidify and cool under reduced pressure.

Processes for producing low nitrogen, essentially nitride-free chromium or chromium plus niobium-containing nickel-based alloys include charging elements or compounds which do not dissolve appreciable amounts of nitrogen in the molten state to a refractory crucible within a vacuum induction furnace, melting said elements or compounds therein under reduced pressure, and effecting heterogeneous carbon-based bubble nucleation in a controlled manner. The processes also include, upon cessation of bubble formation, adding low nitrogen chromium or a low nitrogen chromium-containing master alloy with a nitrogen content of below 10 ppm to the melt, melting and distributing said added chromium or chromium-containing master alloy throughout the melt, bringing the resulting combined melt to a temperature and surrounding pressure to permit tapping, and tapping the resulting melt, directly or indirectly, to a metallic mold and allowing the melt to solidify and cool under reduced pressure.

The invention belongs to the field of chemical separation, hydrometallurgy and resource recovery and provides a method for preparing and applying of ion-keeper adsorbent. By adjusting the pH to selective oxidation to achieve the oxidation of ferrous iron into ferric iron. Separates the iron after the hydrothermal reaction; By using of ion imprint “ion keeper” effect and biomass as raw materials, to prepare the adsorbent with internal rules, hierarchical pores and high selectivity. It can be used for deep purification of chromium solution, such as iron, aluminum, vanadium and other impurities in the solution; After the deep purification of chromium solution, then adjusting the pH, adding appropriate hydrating agent, by hydrothermal precipitation treatment of chrome, filtration, acid washing and calcination to obtain chromium oxide crystal. It achieves the purification of chromium, iron, aluminum and chromium. The recycling and comprehensive utilization of waste resources are also realized. The process is simple, the iron, aluminum, vanadium and other impurities are in the selective adsorption. Chromium solution after deep purification can be processed for high purity chromium products to provide technical support.

The invention belongs to the field of chemical separation, hydrometallurgy and resource recovery and provides a method for preparing and applying of ion-keeper adsorbent. By adjusting the pH to selective oxidation to achieve the oxidation of ferrous iron into ferric iron. Separates the iron after the hydrothermal reaction; By using of ion imprint “ion keeper” effect and biomass as raw materials, to prepare the adsorbent with internal rules, hierarchical pores and high selectivity. It can be used for deep purification of chromium solution, such as iron, aluminum, vanadium and other impurities in the solution; After the deep purification of chromium solution, then adjusting the pH, adding appropriate hydrating agent, by hydrothermal precipitation treatment of chrome, filtration, acid washing and calcination to obtain chromium oxide crystal. It achieves the purification of chromium, iron, aluminum and chromium. The recycling and comprehensive utilization of waste resources are also realized. The process is simple, the iron, aluminum, vanadium and other impurities are in the selective adsorption. Chromium solution after deep purification can be processed for high purity chromium products to provide technical support.

A direct reduction process for the production of ferrochrome from chromite ore or concentrate is disclosed. According to the present invention, calcium chloride (CaCl.sub.2) is added as a catalyst to accelerate the solid reduction and enhance the particle growth of the metallic phase (i.e. ferrochrome) during reduction. The reduction of chromite ore or concentrate takes place at much lower temperatures (e.g. 1200 to 1400° C.) compared to the conventional smelting technologies, and the ferrochrome particles formed are segregated from the unwanted residual gangue and spinel particles, facilitating their subsequent physical separation.

A method of processing red mud comprising: heating red mud to a predetermined temperature; grinding the red mud to a predetermined particle size; and physically extracting iron components from the red mud; physically extracting aluminum components from the red mud, said physically extracting of aluminum components being separate from the physically extracting of iron components, wherein the steps of physically extracting iron components and physically extracting aluminum components are performed without requiring addition of chemical additives to the red mud.

A method of processing red mud comprising: heating red mud to a predetermined temperature; grinding the red mud to a predetermined particle size; and physically extracting iron components from the red mud; physically extracting aluminum components from the red mud, said physically extracting of aluminum components being separate from the physically extracting of iron components, wherein the steps of physically extracting iron components and physically extracting aluminum components are performed without requiring addition of chemical additives to the red mud.

This invention relates to a method for controlling exothermic reactions between metal chlorides of Zn, V, Cr, Co, Sn, Ag, Ta, Ni, Fe, Nb Cu, Pt, W, Pd, and Mo, and Al and the use of the method for preparation of metallic alloys and compounds based on base metals Zn, V, Cr, Co, Sn, Ag, Ta, Ni, Fe, Nb Cu, Pt, W, Pd, and Mo. The method provides for a mixture of precursor chemicals including at least one solid base metal chloride to be mixed and reacted exothermically with a control powder based on Zn, V, Cr, Co, Sn, Ag, Ta, Ni, Fe, Nb Cu, Pt, W, Pd, and Mo and then reacting the resulting intermediates with an Al scavenger. Reduction is carried out in a controlled manner to regulate reaction rates and prevent excessive rise in the temperature of the reactants and the reaction products.

A direct reduction process for the production of ferrochrome from chromite ore or concentrate is disclosed. According to the present invention, calcium chloride (CaCl.sub.2) is added as a catalyst to accelerate the solid reduction and enhance the particle growth of the metallic phase (i.e. ferrochrome) during reduction. The reduction of chromite ore or concentrate takes place at much lower temperatures (e.g. 1200 to 1400 C.) compared to the conventional smelting technologies, and the ferrochrome particles formed are segregated from the unwanted residual gangue and spinel particles, facilitating their subsequent physical separation.

The present invention discloses a method for detoxifying chromium slag by using high sulfur coal. The method includes: sieving chromium slag into coarse-grained chromium slag and fine-grained chromium slag, air-drying and crushing both the coarse-grained chromium slag and the fine-grained chromium slag; separately mixing the crushed coarse-grained chromium slag and fine-grained chromium slag with the crushed high sulfur coal uniformly; adjusting pH values of a coarse-grained slag mixture and a fine-grained slag mixture to 8.0-11.0 and moisture content thereof to 12%-18%; conducting reduction on the treated coarse-grained slag mixture and fine-grained slag mixture, where the reduction temperature of the fine-grained slag mixture is 500-700 C., the reduction time of the fine-grained slag mixture is 10-30 min, the reduction temperature of the coarse-grained slag mixture is 800-1000 C., the reduction time of the coarse-grained slag mixture is 10-30 min; after the reduction, conducting water quenching, and discharging the product.