CN1058056C

CN1058056C - Process of chlorine complexing oxidation method for slective leaching nickel cobalt copper sulfurized ore

Info

Publication number: CN1058056C
Application number: CN97115175A
Authority: CN
Inventors: 方兆珩
Original assignee: Institute of Chemical Metallurgy CAS
Current assignee: Institute of Process Engineering of CAS
Priority date: 1997-07-28
Filing date: 1997-07-28
Publication date: 2000-11-01
Anticipated expiration: 2017-07-28
Also published as: CN1206747A

Abstract

The present invention relates to the leaching technology of nickel-cobalt-copper mixed sulphide ore. Copper-bearing sodium chloride solutions are taken as leaching agents, and oxygen or air is blown in for two-segment countercurrent agitation leaching; in a first segment of leaching, pH is controlled at 2 to 4, and oxidation-reduction potential is controlled at 380 to 450 mV (relative to AgCl/Ag electrodes); in a second segment of leaching, the pH is controlled at 0.5 to 1 and the potential is controlled at 450 to 850 mV. The present invention leaches nickel-cobalt-copper mixed sulphide ore concentrate, the leaching rate of nickel, cobalt and copper respectively achieves 96% to 99%, 97% to 99%, and 88% to 92%, iron generates oxide which is kept in dipping slag, 85% of sulfur is converted into elementary sulfur, and Fe content in leaching liquor is 0.01 to 0.02 g/l. The present invention is favorable for the leaching liquor to carry out deep processing, and the present invention has obvious application prospect.

Description

The technology of chlorine complexing oxidation method for slective leaching nickel cobalt copper sulphide ores

The present invention relates to hydrometallurgical processes, particularly relate to a kind of processing method that adopts non-ferrous metal element such as nickel cobalt copper in the chlorine complexing oxidation method for slective leaching sulphide ores.

Sulphide ores is one of main mineral resources of extracting the nickel cobalt.From sulphide ores, extract one of method of nickel cobalt at present, be to adopt flotation-pyrometallurgical smelting-electrolytic process integration of sulfuric acid pressure oxidation leaching-insoluble anode, as document (1) (Richard, W.H., Eng.Min.J., 178 (1977), No.5,76.) described, its flow process comprises the ore comminution after flotation obtains nickel, cobalt, copper collective concentrate, collective concentrate is smelted into low nickel matte in electric furnace or flash stove, separate with impurity such as silicate; Low nickel matte is converting with air sulphur removal, iron in converter, gets high ice nickel (copper); High ice nickel carries out the sulfuric acid pressurization and leaches (130-150 ℃, 0.2-0.5MPa oxygen is pressed), and the leaching liquid of acquisition is through sinking after the purifying treatment such as cobalt and copper removal, iron with insoluble anode electrolysis output finished product nickel; After leaching, pressurization soaks the slag melting after electrorefining obtains electrolytic copper.

Because existing technical process operation is many, complex process, investment and production cost height, recovery rate of valuable metals is low.Existing procedure adopts pyrometallurgical smelting to handle the bulk flotation concentrate, contains the magnesium height in the concentrate slag melting is increased, and reduces the magnesium content in the collective concentrate when requiring flotation as far as possible; Low nickel matte adopts and bessemerizes deironing, and the part cobalt enters converter slag, the cobalt rate of recovery low (≤50%); Emit a large amount of SO in the pyrometallurgical smelting ₂, make severe environmental pollution; Adopt pressure oxidation to leach nickel matte, equipment requirements height, operational condition harshness; Adopt sulfuric acid system, cobalt nickel separation difficulty, and current density is low during electrolysis, and plant factor is low.

For addressing the above problem, many contrivers set out from different perspectives, technology some innovative approachs have been proposed, as: the record of AU9536689 patent documentation, the ambrose alloy sulfonium depressed with low-concentration sulfuric acid normal pressure or oxygen leach nickel and copper simultaneously, to the deep-etching effect of equipment, and for example: the CA2064543 patent documentation is put down in writing, and adopts acid FeCl when leaching to reduce strong acid ₃Solution leaches Ni, Co, Cu from sulphide ores, to improve recovery rate of valuable metals, reduce the pollution to environment, and raise the efficiency, and is technical unreasonable owing to itself still existing though aforesaid method can solve some problem that exists in the prior art, as FeCl ₃Be difficult to after the leaching from the leaching mother liquor, isolate valuable metals such as Ni, Co, Cu, implement industrial application and still have big difficulty.

The objective of the invention is to overcome shortcoming and technologic unreasonable part on the prior art, from sulphide ores, extract the total recovery of valuable metals, particularly cobalt such as nickel, copper, and eliminate and mix SO in the vulcanised ore concentrate pyrometallurgical smelting process with raising ₂Pollution to environment, overcome a series of weak points of sulfuric acid system simultaneously, thereby provide a kind of employing cupric sodium chloride solution to do leaching liquid, blast the technology that oxygen or air oxidant carry out the chlorine complexing oxidation method for slective leaching nickel copper cobalt mixing sulphide ores of two sections contrary agitation leachs in the leaching process.

The object of the present invention is achieved like this:

Chlorine complexing oxidation method for slective leaching technology of the present invention is used to leach nickel cobalt copper bulk flotation concentrate.Ambrose alloy cobalt bulk flotation concentrate mainly is made up of pyrrhotite, violarite, pyrite, chalcopyrite and silicate gangue, adopts the cupric sodium chloride solution to make initial leaching liquid, and this leaching liquid is 5～45g/L Cu ²⁺, 40～250g/L NaCl, the cupric ion in the leaching liquid is the delivery agent or the oxidising process catalyzer of oxygen, and the oxidizing reaction of sulfide mineral is accelerated; Leaching divides two sections adverse currents to carry out in stirred autoclave, and every section is controlled at differing temps, redox potential and pH scope, blasts oxygen or air in the leaching process continuously, blasts oxygen or air capacity controlled oxidation reduction potential by adjusting.In the chlorinated solution oxygen leaching process, the chlorination medium solution provides the high-dissolvability of metal ion, suitably certain oxidizing atmosphere has been created in the inflation (air or oxygen) under the pressure, make Ni, Co, Cu oxidation dissolution from sulfide respectively, petrogenic elements such as Si, Mg, Ca are stayed with insoluble silicate form and are soaked in the slag, under control pH condition, Fe is converted into insoluble oxide compound, as rhombohedral iron ore (Fe ₂O ₃), pyrrhosiderite (FeOOH) or limonite (Fe ₅O ₇(OH) 4H ₂O), stay and soak in the slag, thereby reach effective isolating purpose.Its concrete technical process is as shown in Figure 2:

1) nickel cobalt copper mixing sulphide ores enters first section and stirs the leaching still, 75～90 ℃ of leaching temperatures, and control pH value of solution=2～4 and redox potential are at 360～450mV (AgCl/Ag electrode relatively), and leaching liquid is from the mother liquor that leaches of second section leaching.In leaching process, rely on the speed control redox potential of regulating aerating oxygen or air.First section main nickel and cobalt of leaching, simultaneously, under control pH value of solution and redox potential, the iron in the sulfide is converted into oxide compound and does not enter solution, thereby Fe content is reduced to the low-level of 0.01g/L in the leaching mother liquor.In the leaching process, part copper ion in the solution and sulfide reaction generate copper sulfide minerals such as copper glance or copper orchid.

2) leach ore pulp and carry out solid-liquid separation, the leaching mother liquor enters subsequent processing and removes to extract copper, cobalt, nickel;

3) solid materials enters second section agitation leach still, adds initial cupric sodium chloride solution and makes the leaching medium, and this solution can be prepared with isolating leaching mother liquor after first section leaching.Leaching is carried out under a neutral temperature a little less than the solution boiling point (as 100 ℃), and pH value of solution=0.5～1 and redox potential are in 450～850mV (AgCl/Ag electrode relatively) scope.When blasting air oxidant, leaching time is 3～7 hours; Blast oxygen when making oxygenant, leaching time 2～5 hours.

4) leach the back ore pulp and carry out liquid-solid separation, solution enters first section agitation leach still after adding alkali adjustment pH.In the whole leaching process, the sulphur in the 85% above sulfide changes into elementary sulfur, can reclaim elementary sulfur with methods such as flotation from the solid materials after leaching.

The present invention compared with prior art has following outstanding advantage:

Directly leach the bulk flotation concentrate, the total recovery of cobalt is increased substantially, reach more than 90%;

Leaching is compared with existing flow process in normal pressure and middle temperature (75-100 ℃) operation down, and temperature of reaction and working pressure descend significantly, and facility investment and production cost reduce significantly;

Adopt the chlorination medium, be convenient to leach nickel cobalt extracting and separating in the mother liquor;

Control pH value of solution and redox potential in the leaching, iron is not leached basically, leach in the mother liquor iron content very low (0.01～0.02g/L), the iron removal step of nickel electrodeposition catholyte is simplified;

In nickel, the cobalt leaching process, do not consume leach liquor in principle, a consumed cabin air or oxygen go out agent as oxygen, and production cost is low;

Magnesium does not enter leach liquor in the leaching process, does not require magnesium content in the restriction flotation concentrate;

The output elementary sulfur is a byproduct, and no pyrogenic process process is not emitted SO in the process ₂, reduce pollution level significantly, improve operation and living environment.It is a kind of environmentally friendly, clean process method of meeting the sustainable technologies criterion.

The present invention is described in detail below in conjunction with drawings and Examples:

Accompanying drawing 1 is existing process flow diagram, and accompanying drawing 2 is process flow diagrams of the present invention.

Embodiment 1. presses technical process shown in the accompanying drawing 2, and leaching Ni, Co, Cu transform elementary sulfur from a kind of mixed Ni cobalt copper flotation concentrate (7.74%Ni, 0.69%Co, 2.01%Cu and 47.0%Fe and 33.1%S), deposit Fe simultaneously in soaking slag.Concentrate is put into the agitation leach reactor, carry out first section leaching under 85 ℃, this section leaching liquid behind second section leaching mother liquor adjustment pH=2.5 leaches terminal point redox potential 415mV, pH value of solution=2.4, leaching time 3 hours; Second section leaching controlled temperature is 98 ℃, leaching terminal point current potential 640mV, pH=0.9, leaching time 3 hours.When second section leaching, add initial leaching liquid, contain 120g/L NaCl, 21.6g/L Cu ²⁺, pH=0.9.All blast oxygen in two sections leaching processes and make oxygenant, regulate oxygen flow controlled oxidation reduction potential.This mixes vulcanised ore concentrate after two sections leachings, and the leaching yield of Ni, Co, Cu is respectively 98.1%, 97.5% and 89.3%, and elementary sulfur transformation efficiency 87% leaches mother liquor and contains 0.015g/L Fe.

Embodiment 2. leaches a kind of mixed Ni cobalt copper flotation concentrate by technical process shown in the accompanying drawing 2, contain 4.10%Ni, 0.40%Co, 0.69%Cu, 44.4%Fe and 28.6%S, first section leaching carried out under 80 ℃, blast air, control pH=2.6, redox potential 430mV, subsequent leaching 3 hours; Second section leaching carried out at 95 ℃, control pH=1.0, redox potential 580mV, subsequent leaching 4 hours.Initial leaching liquid contains 19.3g/L Cu ²⁺, 120g/L NaCl.Through two sections leachings, the leaching yield of Ni, Co, Cu is respectively 96.8%, 98.5% and 87.5%, and the elementary sulfur transformation efficiency is 88.3%, leaches in the mother liquor to contain 0.01g/L Fe.

A kind of mixed Ni cobalt copper flotation concentrate of embodiment 3. leachings contains l3.1%Ni, 0.70%Co, 4.96%Cu, 48.6%Fe and 32.8%S, and leaching technology is identical with embodiment 1 with condition.Through two sections leachings, the leaching yield of Ni, Co, Cu is respectively 98.8%, 99.5% and 91.5%, and the transformation efficiency of sulphur is 91.3%, leaches in the mother liquor to contain 0.02g/L Fe.

Claims

1. the technology of a chlorine complexing oxidation method for slective leaching nickel cobalt copper mixing sulphide ores, it is characterized in that leaching divides two sections adverse currents to carry out in stirred autoclave, adopt the cupric sodium chloride solution of 5～45g/L Cu2+, 40～250g/L NaCl concentration to make initial leaching liquid, blast oxygen or air oxidant in the leaching process, follow these steps to order and carry out:

1) nickel cobalt copper mixing sulphide ores enters first section agitation leach reactor, leaching liquid is taken from isolating mother liquor after second section leaching, 75～90 ℃ of leaching temperatures, pH=2～4, blast oxygen or air controlled oxidation reduction potential at 360～450mV (AgCl/Ag electrode relatively), subsequent leaching 2～7 hours;

2) leach ore pulp and carry out common solid-liquid separation, the leaching mother liquor after the separation is used to extract nickel, cobalt, copper;

3) solid materials enters second section agitation leach reactor, add initial cupric leaching liquid, control pH value of solution=0.5～1 blasts oxygen or air and makes redox potential reach 450～850mV (AgCl/Ag electrode relatively), subsequent leaching 3～7 hours in the leaching process;

4) second section leaching ore pulp carries out solid-liquid separation, and solid materials discards after being used to reclaim elementary sulfur, and the leaching mother liquor returns first section leaching reactor and makes leaching liquid.

2. by the technology of the described chlorine complexing oxidation method for slective leaching nickel cobalt copper mixing of claim 1 sulphide ores, it is characterized in that: described two sections leach liquors return and add alkali when first section leaching reactor made leaching liquid, keep in pH=2～4 scopes.