CN100386450C

CN100386450C - Cooperated leaching method for low-grade intractable gold mine

Info

Publication number: CN100386450C
Application number: CNB2005100313577A
Authority: CN
Inventors: 巨少华; 唐谟堂; 唐朝波; 杨声海; 何静; 姚维义; 鲁君乐
Original assignee: Central South University
Current assignee: Central South University
Priority date: 2005-03-23
Filing date: 2005-03-23
Publication date: 2008-05-07
Anticipated expiration: 2025-03-23
Also published as: CN1837382A

Abstract

The present invention relates to a cooperated extraction method for wet smelting low-grade and difficultly processed gold ores. Ores are directly leached in heaps or in a trough after crushed and milled by the matching leaching agent prepared by the ammonium salt with low concentration, ammonia water and an oxidizing agent to produce leachate with low impurity content and high gold concentration. The leachate can extract the gold in conventional methods, such as replacement, activated carbon adsorption or resin exchange, etc., and the leachate regenerates a matching leaching agent which returns to be utilized. The method has the advantages of simple manufacturing process, short flow process, high leaching speed, high leaching rate, low cost, no cyanidation and no toxin. The present invention is a gold extracting method which easily realizes industrial production and has good economic benefit and environmental benefit.

Description

The cooperated leaching method of low-grade intractable gold mine

[technical field]

The present invention relates to nonferrous metallurgy and from gold mine, cooperate a kind of method that leaches gold, particularly from low-grade copper gold or year charcoal gold mine, cooperate the method for soaking gold.

[background technology]

For smelting process low-grade, difficult-treating gold mine, mainly can be divided three classes: the first kind is that traditional xanthate-black powder associating flotation process obtains gold ore,, leaches charcoal absorption, last desorb, electrodeposition again through roasting with prussiate.This method rate of recovery is low, generally has only 50%, and the cost height, and there is the pollution of sulfur dioxide flue gas and prussiate in long flow path.Second class is to adopt lower concentration cyanide solution direct leaching in dumps low-grade gold, adopts activated carbon column absorption then, desorb again, electrodeposition.This method advantage is that cost is low, uses comparatively extensive in developed countries such as the U.S..But serious threat is caused to environment in this method polluted underground water source.The 3rd class is to adopt lower concentration thiosulphate and ammonia soln direct leaching in dumps low-grade gold, and then displacement, pyrorefining.This method has been owing to adopted the lower thiosulphate of toxicity as leaching agent, study in the world at present more, but since the thiosulphate instability easily decompose, real industrialized and few.

[summary of the invention]

The cooperated leaching method that the purpose of this invention is to provide a kind of low-grade intractable gold mine.

The objective of the invention is that technical scheme by following dump leaching or drill traverse realizes:

At first the mixing ore deposit of exploiting out is broken into qualified muck or continues fine grinding and become breeze, again by certain method group heap or in steel basin, the ammonia ammonium salt solution that enforcement contains oxygenant cooperates circulation dump leaching or drill traverse, the leaching agent composition: concentration is 0.1～5mol/L ammonium chloride, concentration is 0.1～0.5mol/L technical grade ammoniacal liquor, liquid-solid ratio is 0.1～3L/Kg ore deposit during dump leaching, and oxygenant can be air and Cu ²⁺, oxygen and Cu ²⁺, clorox, chlorinated lime or single Cu ²⁺, the add-on of oxygenant is: chlorinated lime adds 5g～100g for the per kilogram ore; Clorox per kilogram ore adds 1～25g; Adopt air or oxygen and Cu ²⁺When making oxygenant, in the cooperation leaching agent of copper-containing ore not, allocate the Cu of 0.005～0.05mol/L into ²⁺, the cooperation leaching agent of copper-containing ore does not add Cu ²⁺Use Cu separately ²⁺During as oxygenant, Cu in the leaching agent ²⁺Concentration be 0.01～0.1mol/L.

At last qualified leach liquor is adopted traditional displacement or adsorption method to carry gold and regeneration cooperation leaching agent.

In cooperating leaching process, the principal reaction of generation has:

Au+kNH ₄Cl→AuCl _k ^j-k+k?NH ₄ ⁺+je

In the formula: k is Cl ^-Ligancy, j is the valence mumber of corresponding gold ion.

Oxidation-reduction reaction is:

O ₂+2H ₂O+4e ^-→40H ^-

Cu ²⁺+e ^-→Cu ⁺

C10 ^-+H ₂O+2e ^-→Cl ^-+20H ^-

The present invention has utilized the Cl in the leaching agent ^-Principle and Cu with gold ion formation stable complex ²⁺To soaking gold utensil catalysis or activation are arranged, because Cu ²⁺Have oxidisability, and air is easy to Cu ⁺Be oxidized to Cu ²⁺Thereby, form a kind of oxidation-reduction circulative metabolism.Therefore, when making oxygenant, if gold mine cupric not, then when cooperating leaching agent, preparation allocates the Cu of 0.005～0.05mol/L into air or oxygen ²⁺, then do not need to add Cu in the cooperation leaching agent of copper-containing ore ²⁺

Do not produce the flue gas flue dust in the production process of the present invention, greatly reduce comprehensive cost and scale production investment that resource is extracted, in conjunction with gold mine gold leaching rate 〉=65%, natural gold mine gold leaching rate 〉=92%; Can high-level efficiency, low cost, the few input, contamination-freely extract gold, non-cyaniding is provided for the recycling of difficult-treating gold mine gold, do not have the modern technique that poisons.

[embodiment]

The mixed type mineral of exploitation are crushed to granularity between the 0.5mm to 20mm, carry out dump leaching.The heap height of building heap begins the cooperation leaching agent spray with the definite composition of preparing in advance at 5-8m, then with the leach liquor circulated sprinkling that does not reach certified concentration, cloth liquid intensity 4～25L/ (m ²H), extraction time is 50-150d, and natural gold mine extraction time can be short slightly, can be long slightly in conjunction with the gold mine extraction time.The gold mine that carries out drill traverse must be levigate to 140 orders, presses 2～6: 1 liquid-solid ratio then in steel basin, cooperates down at 20～60 ℃ and leach 2～12h.

With following indefiniteness embodiment the processing condition of method of the present invention are further described, the described per-cent of embodiment all is weight percents.

Embodiment 1 is from low-grade, the unmanageable copper gold in Gansu, and with conventional flotation process enrichment, gold recovery only is 50%.Copper in this copper gold exists with the oxidized ore form, and gold wherein wraps up golden form with atomic little gangue-type and exists, and this gold mine chemical ingredients sees Table 1.

The chemical ingredients of certain low-grade refractory Treatment of Copper gold mine of table 1.

^*Expression g/t

Its raw ore grain graininess is 30～0.1mm, uses 2mol/L NH ₄Cl, 0.2mol/L NH ₄OH, the synthetic glass post of employing Φ 125 * 1500mm carries out 10Kg level post and soaks, and adds chlorinated lime 500g in the ore pillar, leaches 100d, and the leaching yield of gold is 76.4%.

Embodiment 2 adopts above-mentioned low-grade copper bearing gold mine, and is levigate to-200 orders＞80%, gets in the leaching vat that 1Kg joins 8L, adds 20 gram chlorinated lime simultaneously, again with containing 4mol/L NH ₄Cl and 0.5mol/L NH ₄The cooperation leaching agent 5L of OH, agitation leach 12h at room temperature, gold leaching rate reaches 82.5%.

Because the standing stock of the low-grade intractable gold mine of cupric or year carbon are very abundant, rationally, environmentally friendly on the exploiting economy, can substitute cyanide process, the simple and effective gold extracting method that is applicable to such resources development and utilization is when having important practical significance.

Claims

1. one kind cooperates the method that leaches low-grade intractable gold mine, it is characterized in that: with concentration is 0.1～5mol/L ammonium chloride, and concentration is 0.1～0.5mol/L technical grade ammoniacal liquor, and air and Cu ²⁺, oxygen and Cu ²⁺, clorox, chlorinated lime or single Cu ²⁺Oxygenant is prepared and is cooperated leaching agent to leach difficult-treating gold mine, and the leaching mode comprises dump leaching or drill traverse, and the leach liquor that contains gold reclaims golden valuable metal with ordinary method, and regeneration cooperation leaching agent, and recycle cooperates the major technique condition that leaches to be:

Liquid-solid ratio is 0.1～3L/Kg ore deposit during dump leaching, and spray rate is 4～25L/ (m ²H), the time is 50～150d; Liquid-solid ratio is 2～6: 1 during drill traverse, and temperature is 20～60 ℃, and the time is 2～15h.

2. method according to claim 1 is characterized in that, the add-on of described oxygenant is: chlorinated lime adds 5g～100g for the per kilogram ore; Clorox per kilogram ore adds 1～25g; Adopt air or oxygen and Cu ²⁺Make oxygenant, do not allocate the Cu of 0.005～0.05mol/L in the cooperation leaching agent of copper-containing ore into ²⁺Use Cu separately ²⁺As oxygenant, Cu in the leaching agent ²⁺Concentration be 0.01～0.1mol/L.