Abstract

The invention relates to the field of non-ferrous metallurgy, in particular to a method for processing laterite nickel ores with recovery of nickel and cobalt. In a method involving grinding of the ore, roasting of the ore in a reducing atmosphere for selective reducing of nickel and cobalt, cooling the reduced ore in a non-oxidizing atmosphere to a temperature of 150-300°C, and leaching the cooled cinder with transfer, of nickel and cobalt to the solution, the roasting of the ore in a reducing atmosphere is carried out in the temperature range of 700- 800°C, preferably at 725-775°C, and the cooled cinder is leached with sulfuric acid in a weakly acidic medium at a pH of 1.4-3.5, preferably at a pH of 2.5-3.0, at a temperature of 30- 100°C, preferably at 85-95°C for 45-120 minutes, preferably 60-90 minutes. Before roasting, the ore is preferably mixed with a reducing agent: brown (subbituminous) coal in an amount of 3-3.5% of the weight of the ore. In addition, petroleum fuel, such as fuel oil, can be used as a reducing agent. The roasting process is carried out in the rotary kiln or in a vertical multiple- hearth furnace. For selective reduction of nickel and cobalt during roasting, a reducing atmosphere can be created by controlling the ¾ and CO content in the gas atmosphere of the furnace. Under these conditions, the degree of recovery of nickel from the ore is 88-99%, and the degree of recovery of cobalt is 73-84%. When the process is carried out in the established parameters, along with the achievement of a high degree of metal recovery, material flows in the hydrometallurgical conversion decreasing by 2-2.5 times, and the technical and economic parameters of the process as a whole are improved.

IPC Classes  ?

• C22B 23/00 - Obtaining nickel or cobalt
• C22B 1/02 - Roasting processes
• C22B 3/08 - Sulfuric acid

Abstract

The invention relates to the field of non-ferrous metallurgy, and more particularly to a method for processing nickel laterite ores resulting in the direct production of ferronickel in the form of metal granules. Processing nickel laterite ores involves grinding an ore, for example a high-magnesia ore, a solid carbonaceous reducing agent and flux additives, mixing same to produce a charge, subjecting said charge to reduction roasting in a two-stage apparatus consisting of two rotating furnaces interconnected by a transfer chamber, cooling the resulting clinker, and isolating ferronickel from the ground clinker. The flux additives include, in terms of the mass of the ore, 3.5-6.5% СаО, 1.5-10% SiO2, 1-5.5% Al2O3 and 0-0.75%, in terms of F2, fluorine-containing additives. Various calcium-, silicon-, aluminium- and fluorine-containing materials can be used as flux additives, for example limestone, blast furnace slag, clay, low-grade high-silica bauxites, aluminium-containing slags, fluorite, spent cryolite electrolyte, and other enrichment and metal wastes. Kaolin clay containing a minimum of 15-30% Al2O3 and 50-75% SiO2 can be used in an amount of 3-18% of the mass of the ore as SiO2 and Al2O3additives. The solid carbonaceous reducing agent, for example coke breeze, lignite, coal, anthracite or a combination thereof, is introduced in an amount of 6-12% of the mass of the ore, the mixture is briquetted, the briquettes reduced in the first furnace and having a temperature of 1000-1100°C are charged via the transfer chamber into the second furnace, directly into a bath of molten slag. At the same time, a solid reducing agent, namely coke breeze or anthracite, is supplied to the feed zone of the second furnace in an amount of 4-8% of the mass of the ore. The temperature of the melt in the second furnace is maintained within a range of 1275-1350°С, preferably 1275-1325°С. The advantages of the method are reduced energy consumption and improved technical and economic performance indicators.

IPC Classes  ?

• C22B 23/02 - Obtaining nickel or cobalt by dry processes
• C22B 5/10 - Dry processes by solid carbonaceous reducing agents
• C22B 4/06 - Alloys
• C22C 33/04 - Making ferrous alloys by melting

Abstract

The invention relates to the field of metallurgy and can be used for processing high-magnesia lateritic nickel ores so as to directly produce ferronickel. In the method, the following steps are carried out: mixing the ore with a solid reducing agent and with fluxing agents СаСО3, АI2О3 and SiO2; briquetting the obtained charge; reducing roasting of the briquetted charge so as to form a ferronickel ball; and precipitation of the ferronickel from the clinker. During the mixing of the ore with the reducing agent and the fluxing agents, additives of fluorine-containing materials are introduced to the mixture in an amount of 0.5-2.0% in terms of fluorine, and also sulphur-containing materials in an amount of 0.2-1.2% in terms of sulphur, of the mass of the ore. The reducing roasting of the charge is carried out at a maximum temperature of 1150-1225°C. The invention makes it possible to maximally restrict or entirely eliminate the formation of slag skulls, and to improve the performance indicators of the process as a whole.

IPC Classes  ?

• C22B 23/02 - Obtaining nickel or cobalt by dry processes
• C22B 5/10 - Dry processes by solid carbonaceous reducing agents
• C22B 4/06 - Alloys

Abstract

The invention relates to the field of non-ferrous metallurgy and specifically to a method for processing laterite (oxidized nickel) ores with the direct production of ferronickel in the form of metal granules. The method comprises mixing the ore with a solid reducing agent and with fluxing additives, briquetting the resultant mixture, a reduction firing of the briquetted charge in tubular rotary furnaces forming ferronickel lumps and separating ferronickel from ground clinker. The fluxing additives are input into the mixture in the amounts of 6-12% CaCO3, 6-12% Al2O3, 0-10% SiO2 of the mass of the ore, the maximum temperature in the lump formation zone is maintained in the range of 1300-1350ºC, and the content of carbon residue in the clinker slag is maintained in the range of 0.05-0.55%, and preferably within the range of 0.1-0.4%. A mixture of bituminous coal and anthracite or coke is used as the solid reducing agent. The method allows for achieving high performance when firing in order to increase the effectiveness of directly producing ferronickel from high-magnesium silicate nickel ores.

IPC Classes  ?

• C22B 23/02 - Obtaining nickel or cobalt by dry processes
• C22B 5/10 - Dry processes by solid carbonaceous reducing agents
• C22B 4/06 - Alloys

Abstract

The invention relates to a method for processing lateritic (oxidised nickel) ore, containing nickel, cobalt and iron. The method for processing comprises preparing a ferronickel raw material (ferronickel bloom or a cast iron admixture with nickel) by appropriate techniques, and refining the ferronickel raw material in a lateral blast furnace. Furthermore, the lateral blast furnace is supplied with an oxygenated blast, coal and fluxes. The oxygenated blast, coal and fluxes are supplied in the amounts required for: the complete combustion of carbon and hydrogen contained in fuel; complete melting of the metal and slag produced in the process; eliminating admixtures (Si, Cr, C, S, P) and iron to such a degree that the ferronickel produced complies with international standards of quality for the contents of nickel and the specified admixtures. The technical result of the invention is the production of a marketable ferronickel which complies with international standards.

IPC Classes  ?

• C22B 4/06 - Alloys
• C22B 9/10 - General processes of refining or remelting of metalsApparatus for electroslag or arc remelting of metals with refining or fluxing agentsUse of materials therefor
• C22C 33/04 - Making ferrous alloys by melting