CN112322907A

CN112322907A - Method for settling cyanided ore pulp of pyrite cinder

Info

Publication number: CN112322907A
Application number: CN202011240623.8A
Authority: CN
Inventors: 俸富诚; 廖占丕; 郭智斌; 林鸿汉; 王彦君; 李涛
Original assignee: Zijin Mining Group Co Ltd
Current assignee: Zijin Mining Group Co Ltd
Priority date: 2020-11-09
Filing date: 2020-11-09
Publication date: 2021-02-05

Abstract

The invention relates to a method for settling pyrite cinder cyanide ore pulp, which comprises the steps of size mixing, cyaniding, settling and filtering, and also comprises the step of adopting NaOH solution and a conventional flocculating agent as an additive for accelerating settling, so that the turbidity running of the cyanide ore pulp can be reduced, namely lime or sodium carbonate is still added in the size mixing step to adjust the pH value of cyanogen, and 0.1-0.5 kg/m is added at the same time³Adding NaOH solution according to the amount, adjusting the pH value of the ore pulp to 9-11, and sequentially carrying out seven cyanidation processes, or carrying out the cyanidation processes in a first or second settled washing thickener according to the weight of 0.1-0.5 kg/m³The NaOH solution was added, along with the flocculant in the normal amount. The method has the advantages of better and faster sedimentation effect than the method of using the flocculating agent only, solving the problem of 'muddy' phenomenon of the washing thickener, ensuring the normal operation of the sedimentation process, having popularization and application values and the like, and being suitable for the application in the mining and metallurgy industry.

Description

Method for settling cyanided ore pulp of pyrite cinder

Technical Field

The invention relates to a method for settling cyanided ore pulp of pyrite cinder, which is suitable for application in the mining and metallurgy industry.

Background

Gold and silver and other precious metals are commonly associated with pyrite, a gold concentrate product taking the pyrite as a main component is formed after flotation, most gold particles of the ore are wrapped by carrier minerals when the ore is subjected to direct cyaniding leaching, cyanide cannot permeate into the inside of a solid to act with the wrapped gold particles, and therefore cyaniding leaching rate is low, oxidation and desulfurization pretreatment is required before leaching, so that gold and silver embedded in the pyrite are fully exposed, and subsequent leaching and extraction are facilitated. The roasting oxidation method is the most common pretreatment process for desulfurization, has large treatment capacity, simple operation and low investment cost, and can produce sulfuric acid by-products. The fineness of the cinder formed after roasting is equivalent to that of gold concentrate before roasting, the proportion of-0.074 mm can reach more than 90 percent, lime or sodium carbonate is usually adopted to adjust the pH value of an ore pulp system to be 9-11 after the cinder is prepared into ore pulp, and then NaCN is added to leach gold and silver in the ore pulp, and the reaction principle is as follows:

4Au+8NaCN+2H₂O+O₂＝＝4Na[Au(CN)₂]+4NaOH (silver leaching reaction principle is similar to this)

The reaction can leach the gold and silver existing in a solid form to form a gold-containing complex to enter a solution, so that the extraction of gold and silver is realized. In order to further enrich the gold and silver, the leached ore pulp is subjected to effective sedimentation which is an essential step and used for realizing preliminary solid-liquid separation, and the effective sedimentation plays an important role in ensuring the recovery rate of the gold and silver. If the effective sedimentation separation cannot be realized, the subsequent normal replacement of the gold-silver complex solution is influenced, and the turbid running of the cyaniding ore pulp thickener is also caused. Since the pyrite cinder product contains a certain amount of Fe₂(SO₄)₃，Fe₂(SO₄)₃Under the condition of alkaline solution in the cyaniding process, the Fe in the solution³⁺Readily react with OH^-Fe (OH) giving a reddish brown color₃Sol, which will make the normally settleable ore powder difficult to settle. In general, the addition of a flocculating agent substantially enables these small sols to aggregate to Fe (OH)₃Precipitation, the effect of the precipitation can generally meet the production requirement, but the precipitation is not thorough enoughIn particular, Fe (OH) when the roasting charge changes or the particle size is too fine₃Excessive formation of sol, Fe (OH) not being obtained by using a flocculating agent alone₃The sol all settled, however, causing the thickener to "run muddy". The 'turbid' not only affects the recycling of liquid after cyaniding, but also can cause shutdown and production halt of the cyaniding process. In order to realize higher settling efficiency, except increasing the amount of settling water and prolonging the settling time, the flocculating agent with polyacrylamide as a main component is generally added to improve the settling efficiency of ore pulp at present, but the flocculating agent still cannot achieve better settling effect, particularly when the incoming material of a roasting system changes or the granularity of raw ore of roasting feeding becomes fine, the thickening machine often runs muddy, the addition of the conventional flocculating agent cannot achieve a more ideal settling effect, and further the settling process stops production and stops working and other processes cannot run normally.

Therefore, the method for settling the cyanided ore pulp of the pyrite cinder is particularly urgent.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a method for settling cyanided ore pulp of pyrite cinder.

The task of the invention is completed by the following technical scheme:

the invention relates to a method for settling cyanided ore pulp of pyrite cinder, which comprises pulp mixing, cyaniding, settling and filtering, and also comprises the step of adopting NaOH solution and a conventional flocculating agent as an additive for accelerating the settling, so that the turbidity running of the cyanided ore pulp can be reduced.

Compared with the prior art, the invention has the following advantages and effects:

(1) based on the metallurgical physical and chemical principle, the NaOH solution and the flocculating agent are used as the additive for accelerating the sedimentation, and the sedimentation effect is better and faster than that of the flocculating agent which is used only.

(2) The NaOH is selectively added based on its negatively charged electrolyte solution (OH)^-The negative effect of (3), excess positively charged Fe (OH) can be made₃The sol is agglomerated, the particles are enlarged and converted into precipitates, thereby accelerating the sedimentation, and meanwhile, the mineral powder is quickly sedimented, thereby solving the phenomenon of 'running muddy' of the washing thickenerAnd the normal operation of the sedimentation process is ensured, and the method has popularization and application values.

Drawings

FIG. 1 is a schematic flow diagram of a cyaniding and settling procedure of a pyrite cinder cyaniding ore pulp settling method provided by the invention.

The description is described in further detail below with reference to the accompanying drawings.

Detailed Description

As shown in figure 1, the method for settling the cyanided ore pulp of the pyrite cinder, which is provided by the invention, comprises the steps of size mixing, cyaniding, settling and filtering, and also comprises the step of adopting a NaOH solution and a flocculating agent as an additive for accelerating the settling, so that the turbidity running of the cyanided ore pulp can be reduced.

The process of the invention may further be:

in the step of size mixing, lime or sodium carbonate is still added to adjust the pH value of the cyanogen, and 0.1-0.5 kg/m is added³Adding NaOH solution according to the using amount, adjusting the pH value of the ore pulp to 9-11, and sequentially carrying out seven cyanidation processes.

Or after the seventh cyanidation, the concentration of the catalyst is 0.1-0.5 kg/m³NaOH solution was added to prepare for sedimentation.

Or after cyanidation, the mixture enters a first washing thickener or a second washing thickener with three settlings according to the weight of 0.1-0.5 kg/m³The NaOH solution was added, along with the flocculant in the normal amount.

The bottom flow after three times of sedimentation enters a ceramic filter for filtration to obtain cyanogen slag and filtrate.

And replacing the supernatant subjected to the three-step sedimentation with conventional zinc powder to obtain barren solution.

And returning the filtrate and the barren solution to pulp mixing for recycling.

The cyanogen referred to in the document of the application is ore pulp before cyanidation, the washing thickener of sedimentation provides sufficient space for ore pulp sedimentation,

the following further describes embodiments of the present invention with reference to specific examples.

Example 1

Gold and silver are extracted by roasting-acid leaching-cyanidation process in a certain factory, wherein the raw material is mixed mineral source mainly including pyrite, the raw ore enters cyanidation pulp mixing process after roasting-acid leaching-solid-liquid separation process, pH value regulating liquid is prepared by using solute amount of sodium carbonate and caustic soda in the mass ratio of 1:0.1-0.2, cyanided liquid and a certain amount of clear water as solution, the pH value regulating liquid is fully stirred and dissolved and then added into cyanidation ore pulp to regulate the pH value to 9-11, subsequently NaCN solution is added and compressed air is blown in for cyanidation leaching, a proper amount of flocculating agent is added above a washing thickener after cyanidation is completed, and the flocculating agent is settled by three thickeners, the underflow concentration reaches 60-65%, the supernatant is clear and transparent, the solid content is less than 0.1%, a better settling separation effect is achieved, and barren solution and filtrate obtained after underflow filtration and supernatant zinc powder replacement are returned to size mixing for recycling.

By using the scheme of the example, the thickener has no turbid running phenomenon, and can avoid shutdown accidents.

Example 2

Gold and silver are extracted by roasting-cyaniding process in a certain factory, wherein the raw material is a single mineral source mainly including pyrite, the roasted slag of the raw ore is ground by a ball mill to be fine, the proportion of minus 0.074mm reaches more than 90%, the ground slag is subsequently subjected to cyaniding pulp mixing process, pH value adjusting liquid is lime solution, cyaniding leaching is carried out after the pH value is adjusted to 9-11, and 0.1-0.5 kg/m is added into the last cyaniding tank³And meanwhile, adding a flocculating agent with a normal dosage above a subsequent washing thickener, settling by using three thickeners, wherein the concentration of the underflow of the thickener is 60-65%, the supernatant of the thickener is clear and transparent, and the solid content is less than 0.2%, so that a good settling separation effect is achieved, and barren liquor and filtrate obtained after underflow filtration and supernatant zinc powder replacement are returned to be mixed for recycling.

By using the scheme of the example, the thickener has no phenomenon of 'muddy running'.

Example 3

In a certain plant, fine iron powder and sulfuric acid are produced by adopting pyrite concentrate obtained by flotation of copper concentrate, the main component of the pyrite concentrate is pyrite which contains a certain amount of copper and gold and silver, the copper is recovered by adopting a slag acid leaching-acid leaching liquid extraction electrodeposition process, and the gold and silver are recovered by adopting an acid leaching slag cyanidation process. Before cyaniding, the pH of cyanogen is adjusted by lime solution, and because the proportion of pyrite concentrate of-0.074 mm reaches more than 95%, the cyaniding and settling procedure adopts the conventional flocculating agent for settling, a thickener often runs muddy, and the settling effect is not ideal. Adding caustic soda solution to the upper part of the first thickener according to the proportion of 0.1-0.5 kg/m3, simultaneously adding proper flocculating agent for sedimentation, wherein the supernatant of the thickener is clear and transparent, the solid content is less than 0.2%, a better sedimentation separation effect is achieved, and barren solution and filtrate obtained after underflow filtration and supernatant zinc powder replacement are returned to size mixing for recycling.

By using the scheme of the embodiment, the thickener still has no phenomenon of turbidity even though the ore powder is ore pulp with finer ore powder, and the effect of effective and rapid sedimentation is achieved.

The above embodiments are only preferred embodiments of the present invention, but the embodiments of the present invention are not limited by the above embodiments, and other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be regarded as equivalent replacements within the protection scope of the present invention.

Claims

1. A settlement method for cyaniding ore pulp of pyrite cinder includes such steps as mixing ore pulp, cyaniding, settling and filtering, and features that the additive containing NaOH solution and flocculant is used to accelerate the settling, so reducing the turbidity of cyaniding ore pulp.

2. The method as claimed in claim 1, wherein lime or sodium carbonate is added to adjust the pH of the cyanogen in the slurry mixing step, and the amount of the lime or sodium carbonate added is 0.1-0.5 kg/m³Adding NaOH solution according to the using amount, adjusting the pH value of the ore pulp to 9-11, and sequentially carrying out seven cyanidation processes.

3. The method of claim 2, wherein the amount of the cyanide compound is 0.1 to 0.5kg/m or less after completion of the seventh cyanidation³NaOH solution was added to prepare for sedimentation.

4. The method as set forth in claim 2, wherein the washing liquid is introduced into the first or second washing thickener for sedimentation at a concentration of 0.1 to 0.5kg/m³Adding NaOH solution and adding flocculating agent according to normal amount。

5. The method as set forth in claim 3, characterized in that the underflow after three settlings is filtered in a ceramic filter to obtain the cyanogen residue and the filtrate.

6. The method as set forth in claim 3, characterized in that the supernatant after the three-pass sedimentation is replaced with conventional zinc powder to obtain a barren solution.

7. A process according to claim 5 or 6, characterized in that the filtrate and the barren solution are returned to the conditioning cycle.