Select high nickel matte leaching nickel and cobalt with a sulfuric acid solution and lead to the inhibition of the noble metal leaching residue. The leaching is generally composed of two steps of atmospheric pressure leaching and pressure leaching. The metal in the normal pressure leaching section is completely dissolved, the Ni 3 S 2 is partially dissolved, and the Cu 2 S is not dissolved. Under pressure leaching, under the oxidizing condition, Ni 3 S 2 and NiS were almost completely dissolved, and Cu 2 S was partially dissolved. Most of the Ni and Co in the high nickel ruthenium are transferred into the solution, and most of the Cu remains in the leaching slag in the form of CuS and Cu 2 S.
Control the atmospheric pressure leaching end point PH ≥ 6.2, Cu, Fe in the leachate is hydrolyzed and precipitated. In order to remove. In order to remove Co, a component qualified electrolyte is provided for nickel electrowinning. The process uses black nickel (NiOOH) to remove cobalt, and Co 2+ is oxidized to Co 3+ to be hydrolyzed to Co(OH) 3 precipitate for removal, while deep purification removes other Impurities.
The pure NiSO 4 solution obtained by leaching and purifying is electrolyzed by insoluble anode electrolysis. Lead- silver- gold is the anode, and the pure nickel electrode is the cathode, producing an electrowinning nickel product with a purity (Ni+Co) of about 99.99%.
1. The chemical composition of high nickel bismuth 1, high nickel bismuth treated by sulfuric acid selective leaching in Xinjiang Sukang smelting plant and the preparation of raw materials before leaching are required to use sulphuric acid to selectively leaching high nickel bismuth. Dissolved. This high nickel niobium is mainly composed of a copper- nickel alloy, Ni 3 S 2 and CuS three-phase. Nickel is mainly present in the alloy phase and the Ni 3 S 2 phase, copper is present in the Cu 2 S phase and the alloy phase, and iron and cobalt are present in the platinum phase. After the high-nickel crucible is blown, the water is usually quenched into a granular form by quenching in water, and then finely ground with a ball-milled surface to be selectively leached by Fenghengyu acid.
The raw materials of Fukang Smelter are from the water-quenched metallized high-nickel niobium produced by Kalatongke Nickel Mine. After grinding, grading, dewatering and filtering buckles in the grinding and immersing workshop by two-stage ball mill, the particle size is -0.045mm95% or more. A high nickel niobium filter cake containing 8% to 10% water. Its chemical composition is shown in Table 1. The chemical phase analysis of nickel cobalt is shown in Table 2.
Main ingredient | Ni | Cu | Co | Fe | S | Pb | Zn | Mn | As |
content/% | 31.96 | 48.5 | 0.105 | 0.33 | 16.04 | 0.28 | 0.003 | 0.0033 | 0.0008 |
Precious metal element | Au | Pt | Pd | Ag | Os | Ir | Ru | Rh | |
Content / gt-1 | 4.1 | 1.79 | 1.81 | 240 | 0.037 | 0.023 | 0.04 | 0.016 |
Phase | Ni | Co | ||
content/% | proportion/% | content/% | proportion/% | |
alloy | 16.96 | 54.73 | 0.025 | 22.73 |
Sulfide | 12.58 | 40.59 | 0.023 | 20.91 |
Oxide | 1.45 | 4.68 | 0.062 | 56.36 |
Total amount | 30.99 | 100.00 | 0.11 | 100.00 |
Production practice shows that the nickel leaching rate in the alloy phase and sulfide phase of high nickel bismuth is about 95.3%, while the cobalt leaching rate is only 43.6%. If reduction measures are taken in the converter, the leaching of cobalt can be greatly improved. Rate and increase the leaching rate of nickel.
2. Main chemical reaction of high nickel leaching process Selective leaching of nickel and cobalt in high nickel bismuth with sulfuric acid solution inhibits copper and precious metals from leaching slag. The leaching is generally composed of two or more steps of atmospheric pressure leaching and pressure leaching. The metal Ni in the normal pressure leaching section is completely dissolved, and the Ni 3 S 2 portion is dissolved, and the Cu 2 S is not dissolved.
Ni+H 2 SO4=NiSo 4 +H 2
Ni+H 2 SO 4 +1/2O 2 =NiSo 4 +H 2 O
Co+H 2 SO 4 +1/2O 2 =CoSO 4 +H 2 O
The copper in the alloy phase is oxidized and reacts with Ni 3 S 2 under blasting air during leaching:
2Cu+1/2O 2 =Cu 2 O
Cu 2 O+H 2 SO 4 =CuSO 4 +H 2 O+Cu
2Ni 3 S 2 +2Cu 2+ +1/2O 2 =4NiS+2Ni 2+ +Cu 2 O
Under pressure leaching, the following chemical reactions occur under oxidative conditions:
Cu 2 S+H 2 SO 4 +1/2O 2 =CuS+CSO+CuSO 4 +H 2 O
Ni 3 S 2 +H2SO 4 +Cu 2 O=NiSO 4 +2NiS+2NiS+2Cu+H 2 O
NiS+CuSO 4 =NiSo 4 +CiS
Most of Ni and Co in the high nickel ruthenium were transferred to the solution (Ni leaching rate 94%, Co59%), and Cu remained in the slag in the form of CuS and Cu 2 S.
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