Preparation method of polyacrylamide slurry in hydrometallurgy system

Abstract

The invention discloses a preparation method of polyacrylamide slurry in a wet-process smelting system, and relates to the technical field of wet-process smelting, the method comprises the following steps: adjusting polyacrylamide to a high concentration by using clear water, and carrying out secondary dilution by using a wet-process system solution. According to the method disclosed by the invention, the use of the polyacrylamide slurry is realized, the clear water amount is reduced by 50-70% on the basis of not influencing the ore slurry and solid separation effect, and the problems of concentration dilution and volume expansion of a system solution are solved.

Description

Technical Field

[0001] The invention relates to the technical field of hydrometallurgy, and in particular to a method for preparing polyacrylamide slurry in a hydrometallurgy system. Background Art

[0002] In the hydrometallurgical zinc smelting industry, the products from the leaching, pre-neutralization, copper precipitation, indium precipitation and iron removal processes are generally slurries (solutions containing solids). These slurries require liquid-solid separation. The traditional liquid-solid method is to add polyacrylamide slurry to the slurry and overflow them into a thickening tank to accelerate the liquid-solid separation. However, in the prior art, polyacrylamide is added to the slurry after slurry adjustment. Slurry adjustment requires the use of clean water, and the slurry adjustment concentration is not easy to be high. This will cause a large amount of clean water to enter the hydrometallurgical zinc smelting system, causing problems such as dilution of the system solution and volume expansion. In particular, when the amount of slag in the system is large, the consumption of polyacrylamide increases, resulting in dilution of the system solution and more obvious volume expansion.

[0003] Therefore, providing a method for preparing polyacrylamide slurry that reduces dilution and volume expansion of system solution is a technical problem that needs to be solved urgently in the art. Summary of the invention

[0004] In order to solve the above problems, the present invention provides a method for preparing polyacrylamide slurry in a wet smelting system, wherein the polyacrylamide is first adjusted to a high concentration using clean water, and then diluted twice using a wet system solution to reduce the amount of clean water used and achieve the use conditions of the polyacrylamide slurry without affecting the ore slurry and solid separation effects.

[0005] In order to achieve the above object, the present invention adopts the following technical solution:

[0006] A method for preparing polyacrylamide slurry in a wet smelting system, wherein the method of use first dilutes the polyacrylamide into a high-concentration slurry, and then directly performs secondary dilution through a system solution.

[0007] Preferably, the high-concentration slurry is diluted with clean water.

[0008] Preferably, the concentration of the high-concentration slurry is 3-4 g / L. The polyacrylamide can be fully dissolved by slurry adjustment at this concentration, and the amount of clean water is reduced by 3-4 times, which is one of the effective measures to control the system volume.

[0009] Preferably, the temperature of the clean water is 30-60° C., at which temperature the polyacrylamide dissolution effect is best.

[0010] Preferably, the slurry preparation time of the high-concentration slurry is not less than 1 hour. If it is shorter than this time, the polyacrylamide will not be fully dissolved, the polyacrylamide will be wasted, and the synchronization effect will also be reduced.

[0011] Preferably, the rotation speed of the slurry adjustment is 30-40 rpm.

[0012] Preferably, the system solution uses a middle supernatant. The main reason for using this solution is that the middle supernatant production stage also uses polyacrylamide slurry, which has high requirements for solution impurities, while other systems use polyacrylamide slurry with low impurity requirements.

[0013] Preferably, the intermediate supernatant comprises any one of a second-stage supernatant, a first-stage supernatant, a low-zinc liquid and flotation wastewater, wherein the first-stage supernatant is a first-stage oxygen pressure leaching liquid, the second-stage supernatant is a second-stage leaching liquid, the flotation wastewater is a filtrate produced after flotation of the second-stage leaching residue, and the low-zinc liquid is other slag filtrate in the system.

[0014] Preferably, the concentration of the secondary dilution is 0.5-1.5 g / L.

[0015] Preferably, the slurry preparation time of the secondary dilution is not less than 1 hour.

[0016] Preferably, the rotation speed of the slurry adjustment is 30-40 rpm.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The invention uses polyacrylamide to be adjusted to a high-concentration slurry with clean water, and then uses a wet system solution for secondary dilution to achieve the use of the polyacrylamide slurry. On the basis of not affecting the ore slurry and solid separation effect, the amount of clean water is reduced by 50-70%, and the problems of system solution concentration dilution and volume expansion are solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. The drawings in this description are only embodiments of the present invention.

[0020] Figure 1 The process flow chart of preparing polyacrylamide slurry according to an embodiment of the present invention;

[0021] Figure 2 The state diagram of the polyacrylamide slurry prepared by the experimental production water, the second stage supernatant, the first stage supernatant and the low zinc solution in the embodiment of the present invention;

[0022] Figure 3 The flocculation state diagram of the polyacrylamide slurry prepared by the experimental production water, the second stage supernatant, the first stage supernatant and the low zinc solution in the embodiment of the present invention is explored;

[0023] Figure 4 This is a state diagram of preparing polyacrylamide slurry from experimental production water and mineral processing wastewater in the embodiment of the present invention;

[0024] Figure 5 The flocculation state diagram of polyacrylamide slurry prepared by experimental production water and mineral processing wastewater in the embodiment of the present invention is explored. DETAILED DESCRIPTION

[0025] Embodiments of the present invention are described below. Examples of the embodiments are shown in the accompanying drawings. The embodiments described with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, but are not to be construed as limiting the present invention.

[0026] Example 1

[0027] like Figure 1 The present invention provides a method for preparing polyacrylamide slurry in a hydrometallurgical system, which specifically comprises the following steps:

[0028] (1) Pour clear warm water (40°C) into the slurry mixing tank, and when the clear warm water is submerged and stirred, feed polyacrylamide evenly through the feeder, and adjust the concentration of polyacrylamide to 4g / L to obtain a high-concentration slurry; wherein the rotation speed is 30r / min and the slurry mixing time is 1h;

[0029] (2) The high-concentration slurry and the middle supernatant are uniformly introduced into the secondary slurry adjustment tank for dilution, and the concentration of the polyacrylamide slurry is adjusted to 1.5 g / L; wherein the rotation speed is 30 r / min and the slurry adjustment time is 1 h.

[0030] Example 2

[0031] like Figure 1 The present invention provides a method for preparing polyacrylamide slurry in a hydrometallurgical system, which specifically comprises the following steps:

[0032] (1) Pour clear warm water (50°C) into the slurry mixing tank, and when the clear warm water is submerged and stirred, feed polyacrylamide evenly through the feeder, and adjust the concentration of polyacrylamide to 3.5g / L to obtain a high-concentration slurry; wherein the rotation speed is 35r / min, and the slurry mixing time is 1h;

[0033] (2) The high-concentration slurry and the middle supernatant are uniformly introduced into the secondary slurry adjustment tank for dilution, and the concentration of the polyacrylamide slurry is adjusted to 1 g / L; wherein the rotation speed is 35 r / min and the slurry adjustment time is 1 h.

[0034] Example 3

[0035] like Figure 1 The present invention provides a method for preparing polyacrylamide slurry in a hydrometallurgical system, which specifically comprises the following steps:

[0036] (1) Pour clear warm water (55°C) into the slurry mixing tank, and when the clear warm water is submerged and stirred, feed polyacrylamide evenly through the feeder, and adjust the concentration of polyacrylamide to 3g / L to obtain a high-concentration slurry; wherein the rotation speed is 40r / min and the slurry mixing time is 1h;

[0037] (2) The high-concentration slurry and the middle supernatant are uniformly introduced into the secondary slurry adjustment tank for dilution, and the concentration of the polyacrylamide slurry is adjusted to 1.5 g / L; wherein the rotation speed is 40 r / min and the slurry adjustment time is 0.5 h.

[0038] Experiment

[0039] 1. Experiment: 1.5 g of polyacrylamide was taken at the neutralization and iron removal site, and the polyacrylamide concentration was adjusted to 3 g / L using production water to obtain a high-concentration slurry; the dilution solution selected was production water, second-stage supernatant, first-stage supernatant, and low-zinc solution, and the high-concentration slurry was diluted to a concentration of 1.0 g / L using the above solutions to obtain a polyacrylamide slurry (the relevant parameters and steps are the same as those in Example 2). The state of the solution after dilution is shown in FIG. Figure 2 , from left to right are production water, second stage supernatant, first stage supernatant, low zinc solution; among them, second stage supernatant: free acid 30-70g / L, zinc 80-110g / L, iron 5-20g / L, no solid content; first stage supernatant: free acid 5-15g / L, zinc 110-150g / L, iron 1-5g / L, no solid content; low zinc wash water: zinc 5-80g / L, acid 0-15g / L, no solid content;

[0040] Take 500ml of the first leaching solution, add 10ml of the prepared polyacrylamide slurry, settle for 5min, and the residue drops to the position of 250ml. The relevant state diagram is shown in Figure 3 , from left to right are production water, second stage supernatant, first stage supernatant, and low zinc solution. It can be seen from the figure that the supernatant after flocculation of the polyacrylamide slurry prepared from production water, second stage supernatant, and first stage supernatant is red, while the supernatant after flocculation of the polyacrylamide slurry prepared from low zinc solution is not red and is relatively clear;

[0041] 2. Comparative experiment on pulping of produced water and flotation wastewater

[0042] In the experiment, 1.5 g of polyacrylamide was taken at the neutralization and iron removal site, and the polyacrylamide concentration was adjusted to 3 g / L using production water to obtain a high-concentration slurry; the dilution solution selected production water and flotation wastewater, and the high-concentration slurry was diluted to 1.0 g / L using the above solutions (the relevant parameters and steps are the same as those in Example 2) to obtain a polyacrylamide slurry. The state of the solution after dilution is shown in FIG. Figure 4 , from left to right are produced water and flotation wastewater;

[0043] Take 500ml of the first leaching solution, add 10ml of the prepared polyacrylamide slurry, let it settle for 5min, and the residue drops to the position of 250ml. Then add 5ml of the prepared polyacrylamide slurry again until the sedimentation is completed and the residue drops to the position of 150ml. See the relevant state diagram for details. Figure 5 , from left to right are production water and flotation wastewater. It can be seen from the figure that the supernatant of the polyacrylamide slurry prepared from production water and flotation wastewater after flocculation is red in color;

[0044] in conclusion

[0045] (1) It can be seen from the phenomenon that the clarification effect after slurry preparation using produced water, second-stage supernatant, first-stage supernatant, and floating wastewater is consistent, and the supernatant is red in color; the clarification effect after slurry preparation using low-zinc solution is better, and the supernatant is not red in color;

[0046] (2) Experiments show that the effect of secondary slurry adjustment with flocculants is consistent with or better than that of slurry adjustment with produced water. Therefore, secondary slurry adjustment with flocculants can meet production requirements and ensure the sedimentation effect of the thickener.

[0047] (3) In combination with actual production, it is recommended that flotation wastewater be selected as the solution for secondary slurry adjustment of flocculants, because the solid content of flotation wastewater can be reduced to a minimum after filter pressing, while increasing the open circuit of flotation wastewater;

[0048] (4) Use flotation wastewater for secondary pulping with flocculants. 900 kg of flocculants are used every day, so 225-300 m3 of flocculants are required every day. 3 To produce water, 600m3 is required 3 Flotation wastewater; production water is reduced by 300-500m3 per day 3 , reducing the volume expansion problem from the source, and the reduced production water can be used to wash slag, reducing the soluble zinc in slag water and further improving metal recovery.

[0049] (5) After dilution with flotation wastewater (minimum value is 5.5 g / L, maximum value is 9.8 g / L, average value is 7.5 g / L), the flocculant solution contains high iron (the iron content of the supernatant after iron removal rises to 45-60 mg / L); the treatment method is as follows:

[0050] Method 1: the flocculant in the neutralization stage is used in the old system for slurrying, and the new flocculant system is used in the first and second stages of oxygen pressure leaching;

[0051] Method 2: Use the iron removal supernatant from the secondary slurry of the flocculant, 300-500m3 per day. 3 , waste iron removal solution and increase the system solution circulation volume;

[0052] The third method is to separate the oxygen pressure leaching and the neutralization flocculant, which requires the addition of an intermediate tank and a stirring system.

[0053] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing polyacrylamide slurry in a hydrometallurgical system, characterized in that: The method adopts secondary dilution, wherein the polyacrylamide is firstly diluted into a high-concentration slurry, and then the secondary dilution is directly performed through the system solution.

2. The method for preparing polyacrylamide slurry in a hydrometallurgical system according to claim 1, characterized in that: The high-concentration slurry is diluted with clean water.

3. The method for preparing polyacrylamide slurry in a hydrometallurgical system according to claim 1, characterized in that: The concentration of the high-concentration slurry is 3-4 g / L.

4. The method for preparing polyacrylamide slurry in a hydrometallurgical system according to claim 2, characterized in that: The temperature of the clean water is 30-60°C.

5. The method for preparing polyacrylamide slurry in a hydrometallurgical system according to claim 1, characterized in that: The slurry preparation time of the high-concentration slurry and the secondary dilution is not less than 1 hour.

6. The method for preparing polyacrylamide slurry in a hydrometallurgical system according to claim 5, characterized in that: The rotation speed of the slurry adjustment is 30-40 rpm.

7. The method for preparing polyacrylamide slurry in a hydrometallurgical system according to claim 1, characterized in that: The system solution adopts a middle supernatant.

8. The method for preparing polyacrylamide slurry in a hydrometallurgical system according to claim 1, characterized in that: The intermediate supernatant includes any one of the second stage supernatant, the first stage supernatant, the low zinc solution and the flotation wastewater.

9. The method for preparing polyacrylamide slurry in a hydrometallurgical system according to claim 1, characterized in that: The concentration of the secondary dilution is 0.5-1.5 g / L.

10. The method for preparing polyacrylamide slurry in a hydrometallurgical system according to claim 9, characterized in that: The rotation speed of the slurry adjustment is 30-40 rpm.

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