CN1213007A

CN1213007A - Method and system for extracting noble metal adsorbed on active carbon

Info

Publication number: CN1213007A
Application number: CN98117622A
Authority: CN
Inventors: 李文建
Original assignee: Individual
Current assignee: Individual
Priority date: 1998-08-24
Filing date: 1998-08-24
Publication date: 1999-04-07

Abstract

A process for extracting noble metals adsorbed on activated carbon features that the activated carbon which has adsorbed noble metal is loaded in desorption column while desorption liquid is pumped into the desorption column and the noble metal is electronically deposited. The working pressure is 0.3-10 MPa for desorption column or 0.15-0.8 MPa for electric depositor. The working temp of system is 101-190 deg.C. Said system is a closed one. Its advantages are short desorption and deposition time and no environmental pollution.

Description

Be adsorbed on the extracting method and the system of the precious metal on the gac

The present invention relates to a kind of extracting method and system that is adsorbed on the precious metal on the gac, belong to the refinement field of cyanide process precious metal.

Present most of gold mine all adopts carbon-in-pulp process or carbon-in-leach process direct production gold.Gold in the dissolves into solution, is added gac by prussiate toward solution in from ore under the condition of aerobic, gac is ADSORPTION OF GOLD and become and carry a golden charcoal just, and then reclaims the gold that carries on the golden charcoal by certain method, through smelting output finished product ingot.Reclaim the method for carrying the gold on the golden charcoal and roughly have following three kinds: the one, the Zadra method is invented by the Zadra of United States Bureau of Mines.It is to accumulate in earlier in the storage charcoal groove carrying golden charcoal, after enough a certain amount of, pack in the desorb post, in the desorb liquid bath, be made into stripping liquid with about 1% NaOH and about 2% violent in toxicity NaCN and water then, under the state that heats up, driven by recycle pump, stripping liquid forms circulation continuously by the desorb post that carries golden charcoal, strainer, heat exchanger, Winning cell, well heater etc. are housed successively.During by the desorb post, the gold that carries on the golden charcoal is got off to enter in the stripping liquid by desorb constantly; During by Winning cell, gold is separated out from solution under the effect of voltage and current and is deposited on the negative electrode of Winning cell.In the method, Winning cell is exposed in the atmosphere, the service temperature of system is between 90～100 ℃, volatilize unpleasant toxic gas during work constantly, the working hour of a collection of year golden charcoal of desorb electrodeposition is 30～50 hours, poor charcoal grade finally is many more than 350 grams per ton, and this method working hour is long, poor charcoal is of high grade, cost is high, the harm operator is healthy, contaminate environment also needs more energy keep the system works temperature.The 2nd, AARL method, this method are to be released by Great Britain and America's research trial institute (AARL) in South Africa.It is to carry out pickling with hydrochloric acid earlier with carrying golden charcoal, the desorb post of then packing into, NaOH with about 5% added about 1% NaCN preimpregnation 0.5～1 hour, the preimpregnation temperature is 110 ℃, pressure is 0.1～0.2 MPa, the pure water of reusable heat or deionized water carry out desorb to charcoal, and desorption effect is very responsive to water quality, and the flow process of desorb electrodeposition is with the Zadra method.The working hour of a collection of year golden charcoal of AARL method desorb electrodeposition is 8～10 hours, shorten greatly than Zadra method, but it still has other shortcoming of Zadra method, and again than Zadra fado one cover pure water preparation device, equipment is complicated more.The 3rd, the solvent desorption method, be in stripping liquid, to add organic solvent, as ethanol, acetone etc., it is that organic solvent, 0.2～2% NaOH with 20～40% and 0.1～1% NaCN carry out desorb to carrying a golden charcoal, normal pressure is operation down, temperature is 25～80 ℃, and stripping liquid is separated out gold through electrodeposition, and technical process is with the Zadra method.The working hour of a collection of year golden charcoal of this method desorb electrodeposition is 5～6 hours, but the organic solvent of its use is the toxic and volatile inflammable explosive article, and volatilization loss has also improved working cost except that polluting; In addition, fire danger and drop to minimumly, also a lot of safety features must be set for making.Chinese patent CN1131442A discloses a kind of elution process that is adsorbed on the precious metal on the gac, is to the standard eluent solution, for example has or do not have in the pure NaOH--NaCN eluent solution to add strong reductant; This method still can not solve problems such as poor charcoal is of high grade, cost is high, the harm operator is healthy, contaminate environment.

The object of the present invention is to provide a kind of desorb electrodeposition time short, poor charcoal grade is low, operator's health is not had the method and system that harm, environmentally safe, the lower-cost precious metal that will be adsorbed on the gac are extracted.

The object of the present invention is achieved like this:

A kind of extracting method that is adsorbed on the precious metal on the gac, it is pack into desorb post and pump into stripping liquid and carry out desorb of the gac that will be adsorbed with precious metal earlier, then the expensive liquid of desorb is entered Winning cell and carry out electrodeposition, stripping liquid behind the electrodeposition enters the desorb post again, circulating desorption, electrodeposition according to this, thus precious metal obtained, and the operating pressure in the desorb post is 0.3～1.0 MPa, operating pressure in the Winning cell is 0.15～0.8 MPa, and the system works temperature is 101～190 ℃.

Described stripping liquid is sodium hydroxide (NaOH) solution, and its concentration is below 5%.

A kind of extraction system that realizes aforesaid method, comprise storage charcoal groove, desorb post, strainer, Winning cell, recycle pump, well heater, desorb liquid bath, storage charcoal groove and desorb post join, the desorb post goes out end and is connected to strainer, Winning cell, recycle pump, well heater in turn, the end that goes out of well heater joins with desorb post inlet side, desorb liquid bath and recycle pump join, system also comprises air compressor, and air compressor and desorb post, strainer, Winning cell, recycle pump, well heater constitute the work system of a sealing.

When being stored in enough one batch of the amounts of activated carbon that is adsorbed with precious metal in the storage charcoal groove, gac is finished pickling in this groove, rinsing, put into then in the desorb post, in the desorb liquid bath, be made into the stripping liquid of suitable concn with NaOH and water, with recycle pump stripping liquid is charged into system, in system, fill in the into quantitative stripping liquid, by air compressor or similar devices system is boosted to 0.1～0.3 MPa, under the driving of recycle pump, after the heating installation heating of stripping liquid by electric heater or other form, enter the desorb post gac is carried out desorb, enter the Winning cell electrodeposition after the expensive liquid of desorb filters through filter and take off precious metal, then enter recycle pump and circulate, going round and beginning again directly causes the end of a period of desorb electrodeposition.

The present invention has following advantage than prior art: (1) is owing to pressure height, working temperature height, thereby reaction is fast, the desorb electrodeposition cycle is short, generally below 14 hours; (2) desorption efficiency, electrodeposition rate height, thus poor charcoal grade is low, is generally less than 80 grams per ton; (3) owing to do not use the cyanogen material that contains of costliness, severe toxicity to make strippant, thereby it is lower that operator's health is not had harm, environmentally safe, cost; (4) because extraction system is sealed, and it is less therefore to dispel the heat, only need less energy to keep the system works temperature.

Below in conjunction with drawings and Examples the present invention is described in further detail:

Accompanying drawing is the structure iron of extraction system of the present invention.

A kind of extraction system that is adsorbed on the precious metal on the gac, comprise storage charcoal groove 1, desorb post 2, strainer 3, Winning cell 4, recycle pump 5, well heater 6, desorb liquid bath 7, storage charcoal groove 1 joins with desorb post 2, the desorb post goes out end and is connected to strainer in turn, Winning cell, recycle pump, well heater, Winning cell is sealed Winning cell, the end that goes out of well heater joins with desorb post inlet side, desorb liquid bath and recycle pump join, system also comprises air compressor 8, all use pipe connection between each parts, air compressor and desorb post, strainer, Winning cell, recycle pump, well heater constitutes the work system of a sealing, so that make this intrasystem pressure can be higher than normal pressure.

A kind of extracting method that is adsorbed on the precious metal on the gac, this gac is for carrying golden charcoal, when year golden charcoal amount in being stored in storage charcoal groove reaches one batch, to carry golden charcoal and in this groove, finish pickling, rinsing, put into then in the desorb post, in the desorb liquid bath, be made into 4% stripping liquid with NaOH and water, with recycle pump stripping liquid is charged into system, in system, fill in the into quantitative stripping liquid, by air compressor or similar devices system is boosted to 0.3 MPa, under the driving of recycle pump, after the heating installation heating of stripping liquid by electric heater or other form, enter the desorb post and carry out desorb to carrying golden charcoal, the expensive liquid of desorb enters Winning cell electrodeposition degold after filtering through filter, then enter recycle pump and circulate, going round and beginning again directly causes the end of a period of desorb electrodeposition.Operating pressure in the desorb post is 0.6 MPa, and the operating pressure in the Winning cell is 0.5 MPa, and the system works temperature is 155 ℃.The desorb electrodeposition time is 14 hours, and poor charcoal grade is 80 grams per ton.

Claims

1, a kind of extracting method that is adsorbed on the precious metal on the gac, it is pack into desorb post and pump into stripping liquid and carry out desorb of the gac that will be adsorbed with precious metal earlier, then the expensive liquid of desorb is entered Winning cell and carry out electrodeposition, stripping liquid behind the electrodeposition enters the desorb post again, circulating desorption, electrodeposition according to this, thus precious metal obtained, and it is characterized in that: the operating pressure in the desorb post is 0.3～1.0 MPa, operating pressure in the Winning cell is 0.15～0.8 MPa, and the system works temperature is 101～190 ℃.

2, extracting method according to claim 1 is characterized in that described stripping liquid is sodium hydroxide (NaOH) solution, and its concentration is below 5%.

3, a kind of extraction system that realizes the method for claim 1, comprise storage charcoal groove, the desorb post, strainer, Winning cell, recycle pump, well heater, the desorb liquid bath, storage charcoal groove and desorb post join, the desorb post goes out end and is connected to strainer in turn, Winning cell, recycle pump, well heater, the end that goes out of well heater joins with desorb post inlet side, desorb liquid bath and recycle pump join, it is characterized in that: this system also comprises air compressor (8), air compressor and desorb post (2), strainer (3), Winning cell (4), recycle pump (5), well heater (6) constitutes the work system of a sealing.