A heavy metal pollutant stabilizer for wolframite beneficiation tailings and a method of application thereof

Abstract

The present application relates to a kind of heavy metal pollutants stabilizer of wolframite beneficiation tailings and its application method, can effectively solve the problem of heavy metal pollution of wolframite beneficiation tailings.The stabilizer composition includes: basic component A and reinforcing component B;Wherein basic component A is 100% with total mass, polyaluminum ferric chloride 30%~50%, calcium hydroxide 10%~50%, calcium carbonate 10%~30%, iron oxide 0.1%~5%;Reinforcing component B is sodium tripolyphosphate, and is prepared into aqueous solution and is used.Polyaluminum ferric chloride, calcium hydroxide, calcium carbonate, iron oxide are finely ground to ≤200 mesh, and are activated, and the basic component A is obtained;Reinforcing component B is prepared into 0.1~3.0% aqueous solution and is used.The present application can realize the solidification and stabilization of heavy metal pollutants in wolframite beneficiation tailings, significantly reduce the leaching of heavy metals in tailings, with good weather resistance, can maintain long-term stability.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tailings treatment, and more particularly to a heavy metal pollutant stabilizer for black tungsten ore dressing tailings and an application method thereof. BACKGROUND

[0002] The black tungsten ore contains not only useful mineral black tungsten (Fe, Mn) WO4, but also pyrite (FeS2), arsenopyrite (FeAsS) and other metal sulfide minerals, and a small amount of metal oxide minerals and metal salt substances oxidized from these sulfide minerals. After the tungsten minerals are extracted from the black tungsten ore through crushing, grinding, gravity separation and flotation, a variety of metal minerals containing heavy metals, including heavy metal sulfide, oxide and sulfate, are left in the tailings. The heavy metal sulfate and sulfite are easily dissolved in water. During the storage of the tailings, the metal sulfide minerals are oxidized due to the joint action of water and oxygen, especially acid rain erosion, resulting in acid and various heavy metal substances easily dissolved in water. Under an acidic environment, the heavy metal oxides in the tailings react with the acid, and the heavy metals are dissolved into water. Therefore, after the black tungsten ore dressing tailings are soaked in water, the heavy metals such as arsenic and cadmium in the tailings are transferred to the water phase, and the concentration can exceed the limit value of the "Integrated Wastewater Discharge Standard" (GB8978-1996). The black tungsten ore dressing tailings are usually judged as Class II solid waste, and even belong to hazardous waste. The black tungsten ore dressing tailings have a great risk of heavy metal pollution to the ecological environment. It is an urgent and important environmental and social problem to realize the harmless disposal of the black tungsten ore dressing tailings.

[0003] The patent with the publication number CN106669964B discloses a beneficiation method for recovering black tungsten from tailings, which only relates to the recovery of black tungsten from tailings and does not involve the safe disposal of black tungsten ore dressing tailings. SUMMARY

[0004] The present application solves the technical problem of providing a heavy metal pollutant stabilizer for black tungsten ore dressing tailings and an application method thereof, which can harmlessly dispose of tungsten ore dressing tailings with arsenic content ≤15000mg / kg. The present application can realize the solidification and stabilization of heavy metal pollutants in the tailings, eliminate the pollution hazards and hidden dangers of black tungsten ore dressing tailings, and greatly reduce the environmental pollution risk of the black tungsten mining and dressing industry.

[0005] To solve the technical problem, the present application adopts the following technical solution:

[0006] A heavy metal pollutant stabilizer for black tungsten ore dressing tailings, comprising a basic component A and a reinforcing component B, based on a total mass of 100%.

[0007] The base component A is: polyaluminum ferric chloride 30%~50%, calcium hydroxide 10%~50%, calcium carbonate 10%~30%, iron oxide 0.1%~5%;

[0008] The polyaluminum ferric chloride is an industrial product, and the main components are: aluminum oxide ≥26%, iron oxide 3%~6%, base degree ≥65%, arsenic ≤0.0003%;

[0009] The calcium hydroxide, calcium carbonate and iron oxide are all industrial products;

[0010] Preferably, the calcium hydroide, calcium carbonate and iron oxide are analytical pure products.

[0011] As preferred, the base component A is: polyaluminum ferric chloride 49kg, calcium hydroxide 49kg, calcium carbonate 1.8kg, iron oxide 0.2kg;

[0012] The preparation method of the base component A is that the polyaluminum ferric chloride, calcium hydroxide, calcium carbonate and iron oxide are mixed uniformly according to the proportion, and then are ground in a grinding device to ≤200 mesh, and are activated;

[0013] The grinding device refers to a ball mill, a Raymond mill and the like;

[0014] The reinforcing component B is sodium tripolyphosphate, which is prepared into a water solution with a concentration of 0.1~3.0% for use;

[0015] The reinforcing component B refers to industrial-grade sodium tripolyphosphate;

[0016] Preferably, the reinforcing component B refers to analytical pure sodium tripolyphosphate;

[0017] The heavy metal pollutants are one or more of arsenic and cadmium, and the content of arsenic in the tailings is ≤15000mg / kg.

[0018] The application also provides an application method of the heavy metal pollutant stabilizer for wolframite beneficiation tailings, which comprises the following steps:

[0019] Step one: uniformly mixing the base component A with the wolframite beneficiation tailings at 0.5%~3.0% of the mass to obtain a mixture;

[0020] Step two: preparing the reinforcing component B into a water solution with a concentration of 0.1~3.0%, and adding the mixture obtained in step one to form a solidified and stabilized body with a water content of 20%~30%;

[0021] Step three: stacking the solidified and stabilized body obtained in step two to form a wolframite beneficiation tailings solidified body;

[0022] Step four: the solidified body is cured, and the solidification and stabilization of the heavy metal pollutants in the wolframite beneficiation tailings is completed; the curing time is 24 hours, and excellent effects can be produced;

[0023] Step five: the solidified and stabilized body is exposed to the air for 180 days, and the results show that the effects are still stable.

[0024] As preferred, in step two, the concentration of the aqueous solution is 0.2%; and the water content of the solidified and stabilized body is 25%.

[0025] As preferred, the pH of the solidified and stabilized body obtained in step two is controlled to be 7.5-9 by controlling the amount of the base component A in step one.

[0026] Beneficial effects

[0027] Compared with the prior art, the present application has the following main advantages:

[0028] (1) The polyaluminum ferric chloride, calcium hydroxide, calcium carbonate and iron oxide used in the present application are compounded and mechanically ground to ≤200 mesh, and the physicochemical properties are changed; the finer the particle size of the material, the larger the specific surface area, and the greater the surface free energy. When the stabilizer is less than 200 mesh, and the heavy metal pollutants are one or more of arsenic and cadmium, and the content of arsenic in the tailings is ≤15000 mg / kg, the stabilizer can also be better mixed with the tailings which are also fine, and uniformly distributed between various minerals, under the action of the strengthening component and water, the polyaluminum ferric chloride and calcium hydroxide hydrolyze and immediately react with heavy metals such as cadmium and arsenic, such as reacting with cadmium to generate Cd4Al2O6C l2 10H2O, reacting with arsenic to generate Al2(AsO4)(OH)3·3H2O, etc., while complex agglomeration, polymerization, physical adsorption and other physicochemical mineralization effects are generated; the heavy metals such as arsenic, copper and lead form multi-nuclear polymers with iron and aluminum, and are solidified together, greatly reducing the toxicity and leaching rate of heavy metals; the trisodium phosphate is selected as a reinforcing agent, and cooperates with the base component A to make the heavy metal minerals generated in the solidification and stabilization process more stable, and the heavy metal pollutants leached after stabilization are far lower than the limit value of the "Integrated Wastewater Discharge Standard" (GB8978-1996), and the wolframite beneficiation tailings are changed from Class II solid waste to Class I solid waste, and the environmental pollution risk is greatly reduced. It can be seen that the heavy metal pollutant stabilizer for wolframite beneficiation tailings of the present application is a kind of heavy metal solidification and stabilization agent which has fast effects and good effects.

[0029] (2) The calcium carbonate and iron oxide in the heavy metal pollutant stabilizer for wolframite beneficiation tailings are difficult to dissolve in water, but can react with acid in acidic aqueous solution, and the acid generated by oxidation of sulfide minerals in the tailings is immediately neutralized by the calcium carbonate and iron oxide, thereby preventing further oxidation and precipitation of various heavy metal minerals in the tailings; the stabilizer also has the function of stabilizing the pH value of the tailings solidified body, and the solidified and stabilized tailings have good weather resistance and can be stable for a long time. The solidification and stabilization of the heavy metal pollutants in the wolframite beneficiation tailings can produce excellent effects in 24 hours, and the solidified and stabilized body can still have stable effects after being exposed to the air for 180 days. Therefore, the leaching toxicity of the heavy metal pollutants in the wolframite beneficiation tailings can be effectively reduced for a long time.

[0030] (3) The stabilizer has low cost and small dosage, and the tailings after treatment have little volume increase; the stabilizer can simultaneously solidify and stabilize arsenic, cadmium and other heavy metal pollutants in the tailings; and the stabilizer will not cause secondary pollution to the environment. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 It is a process flow diagram of the heavy metal pollutant stabilizer for wolframite beneficiation tailings and application of the present application.

[0032] Figure 2 It is an XRD graph of the reaction of the stabilizer of the present application with cadmium (Cd).

[0033] Figure 3 It is an XRD graph of the reaction of the stabilizer of the present application with arsenic (As).

[0034] Figure 4 It is an EDS graph of the formation of a multi-nuclear polymer of iron and aluminum in the stabilizer and arsenic, copper, lead and other heavy metals in the tailings. DETAILED DESCRIPTION

[0035] The present application will be further described below in combination with the drawings and specific embodiments.

[0036] The stabilizer of the present application is composed of a basic component A and a reinforcing component B. The basic component A is prepared by mechanical activation of the following components: polyaluminum ferric chloride, calcium hydroxide, calcium carbonate and iron oxide, and has a particle size of ≤200 mesh; the reinforcing component B is sodium tripolyphosphate, which is prepared into an aqueous solution for use. When the heavy metal pollutants are one or more of arsenic and cadmium, and the content of arsenic in the tailings is ≤15000 mg / kg, the basic component A of the stabilizer is added to the tailings and mixed uniformly, and then the aqueous solution of the reinforcing component B is added. The basic component A can be uniformly distributed between the tailings particles due to its fine particle size, and the stabilizer generates multi-nuclear hydroxyl ions, chain colloids and the like after hydrolysis, which reacts with the free cadmium, arsenic and other heavy metal ions in the tailings to generate Cd4Al2O6Cl2·10H2O, Al2(AsO4)(OH)3·3H2O and a series of substances (see Figure 2, Figure 3 The EDS detection result of the stabilized tailings of the wolframite ore dressing shows that the heavy metals such as arsenic, copper and lead are combined together with the iron and aluminum hydrolytic colloids in the stabilizer to form a multi-core polymer (Example 1). Figure 4 Example 1.

[0037] Control (without adding stabilizer)

[0038] In order to better illustrate the effect of the present application on stabilizing heavy metal pollutants, the leaching toxicity test is conducted on the wolframite ore dressing tailings without adding the stabilizer to investigate the water leaching dissolution of the heavy metal pollutants in the tailings. The content of the heavy metal pollutants in the tailings is 1349.38 mg / kg of arsenic and 189.26 mg / kg of cadmium.

[0039] The treatment method of the present control (without adding stabilizer) is that the wolframite ore dressing tailings without adding the stabilizer are taken to conduct the leaching toxicity test according to the standard requirements of the "Solid Waste Leaching Toxicity Leaching Method Horizontal Oscillation Method" (HJ557-2010). The relevant results are shown in Table 1. As can be seen from Table 1, the content of arsenic and cadmium in the leaching solution of the wolframite ore dressing tailings without adding the stabilizer is high, which exceeds the limit value of the "Integrated Wastewater Discharge Standard" (GB8978-1996). According to the national standard, the wolframite ore dressing tailings belong to the II type of industrial solid waste.

[0040] Example 1

[0041] In order to illustrate the effect of the present application on stabilizing heavy metal pollutants, the heavy metal ions in the heavy metal standard solution are solidified and stabilized according to the heavy metal solidification and stabilization agent and the use method of the present application.

[0042] The preparation of the stabilizer and the method of solidifying the heavy metal ions in the heavy metal standard solution of the present example are as follows:

[0043] Step one: put 49 kg of polyaluminum ferric chloride, 49 kg of calcium hydroxide, 1.8 kg of calcium carbonate and 0.2 kg of iron oxide into a ball mill for grinding, all of which pass through a 200 mesh sieve to obtain a basic component A;

[0044] Step two: take 250 ml of arsenic and cadmium standard solutions with a mass concentration of 1000 mg / L produced by the National Non-ferrous Metal and Electronic Material Analysis and Test Center in a 1000 ml beaker;

[0045] Step three: take 150 g of the basic component A obtained in step one and add it into the beaker in step two for stirring uniformly;

[0046] Step four: 10 mL of the 0.3% reinforced component B (sodium tripolyphosphate) aqueous solution is added to the mixture of the step three base component A and the heavy metal standard solution, and stirred uniformly to obtain a solidified and stabilized body;

[0047] Step five: the solidified and stabilized body of step four is air dried;

[0048] Step six: the solidified and stabilized body of step five is detected by an X-ray diffractometer (XRD for short), and the results are shown in Figure 2 and Figure 3 As can be seen from the figure, the stabilizer reacts with cadmium and arsenic in the standard solution to generate Cd4Al2O6Cl2·10H2O, Al2(AsO4)(OH)3·3H2O and a series of substances;

[0049] Step seven: the solidified and stabilized body of step five is subjected to leaching toxicity test according to the standard requirement of the Solid Waste - Leaching Toxicity Leaching Method - Horizontal Oscillation Method (HJ557-2010). The related results are shown in Table 1. As can be seen from the results, the concentrations of arsenic and cadmium in the leaching solution of the solidified and stabilized body are low, which indicates that the stabilizer of the present application does not dissolve into water after reacting with arsenic and cadmium, and the stabilizer has a good solidification and stabilization effect on arsenic and cadmium.

[0050] Example 2

[0051] In order to illustrate the actual application effect of the present application, the heavy metal pollutants in a certain wolframite ore dressing tailings are subjected to solidification and stabilization control according to the stabilizer and the use method of the present application. The heavy metal content of the certain wolframite ore dressing tailings is 1349.38 mg / kg of arsenic and 189.26 mg / kg of cadmium.

[0052] In combination with Figure 1 , the preparation of the stabilizer and the method for solidifying and treating the heavy metal pollutants in the wolframite ore dressing tailings are as follows:

[0053] Step one: 49 kg of polyaluminum ferric chloride, 49 kg of calcium hydroxide, 1.8 kg of calcium carbonate and 0.2 kg of iron oxide are put into a ball mill for grinding, and all pass through a 200 mesh sieve to obtain a base component A;

[0054] Step two: 500 g of dry weight of a certain wolframite ore dressing tailings is put into a blender;

[0055] Step three: 10 g of the base component A obtained in step one is added to the blender of step two, and is mixed and stirred uniformly with the wolframite ore dressing tailings;

[0056] Step four: 50 mL of 0.3% sodium tripolyphosphate aqueous solution is added to the mixture of step three base component A and wolframite beneficiation tailings, and the mixture is uniformly mixed to form a solidified and stabilized body; the pH of the solidified and stabilized body is 9;

[0057] Step five: the wolframite beneficiation solidified and stabilized body to which the stabilizer is added is cured for 24 hours; and then is exposed to the open air for 180 days;

[0058] Step six: the wolframite beneficiation solidified and stabilized body cured for 24 hours is sampled and subjected to scanning electron microscope (SEM) detection, and the results are shown in Figure 4 It can be seen from Figure 4 that after the addition of the stabilizer, within 24 hours, the stabilizer forms a multi-nuclear polymer with the heavy metal pollutants, and the multi-nuclear polymer is solidified together with the tailing particles through bonding, bridging, net trapping and other effects, so as to achieve the purpose of stabilizing the heavy metals in the tailings and reducing the risk of heavy metal leaching;

[0059] Step seven: the wolframite beneficiation solidified and stabilized body of step five is sampled and subjected to leaching toxicity test according to the standard requirements of “Solid Waste - Leaching Toxicity Leaching Method - Horizontal Oscillation Method” (HJ557-2010). The related results of curing time of 24 hours and 180 days are shown in Table 1.

[0060] The arsenic, cadmium and other heavy metals in the wolframite beneficiation tailings have two phases in terms of solubility, one is easily soluble in water, such as arsenic-containing substances and cadmium-containing substances, and the other is difficult to dissolve in water, such as arsenic-containing minerals and cadmium-containing minerals, but the latter type of arsenic-containing or cadmium-containing minerals is also easy to be oxidized to form easily soluble substances in the presence of water and oxygen. After the stabilizer base component A is uniformly mixed with the wolframite beneficiation tailings, the main effect is to be uniformly distributed in the tailing particles, and after the addition of the aqueous solution of the reinforcing component B (sodium tripolyphosphate), a multi-polar colloid such as aluminum hydroxide and iron hydroxide is formed, which polymerizes arsenic ions and arsenic-containing substances, cadmium ions and cadmium-containing substances, etc. through chemical reaction and adsorption, bonding, bridging, net trapping and other physical effects (see Figure 4), so that the heavy metal pollutants such as arsenic and cadmium cannot be precipitated in water, and play a role of stabilization and solidification; meanwhile, the multi-polar colloids such as aluminum hydroxide and iron hydroxide, and the water-insoluble calcium carbonate and iron oxide in the stabilizer prevent the further oxidation of the arsenic-containing minerals and cadmium-containing minerals in the tailings to generate easily water-soluble arsenic-containing substances and cadmium-containing substances. As can be seen from Table 1, compared with the control example without the stabilizer, due to the fine particle size, uniform distribution, and fast effect of the stabilizer of the present application, the concentration of the heavy metal pollutants arsenic and cadmium in the leaching solution is lower than the limit value of the "Integrated Wastewater Discharge Standard" (GB8978-1996) after 24 hours of curing, and the solidification and stabilization effect of the arsenic and cadmium pollutants is very obvious, and the solidification and stabilization effect does not decrease after 180 days of open storage, and is still stable, which further proves that the mechanism of the stabilizer of the present application for solidification and stabilization of the heavy metal pollutants in the wolframite beneficiation tailings is clear and the effect is outstanding.

[0061] Example 3

[0062] In order to illustrate the practical application effect of the present application, the heavy metal pollutants in a certain wolframite beneficiation tailings are solidified and stabilized by the stabilizer and the use method according to the present application. The heavy metal content of the certain wolframite beneficiation tailings is arsenic 1349.38 mg / kg and cadmium 189.26 mg / kg.

[0063] In combination with Figure 1 , the preparation of the stabilizer and the method for treating the wolframite beneficiation tailings in this example are as follows:

[0064] Step one: put 46 kg of polyaluminum ferric chloride, 45 kg of calcium hydroxide, 8.8 kg of calcium carbonate, and 0.2 kg of iron oxide into a ball mill for grinding, and pass all through a 200 mesh sieve to obtain a stabilizer basic component A:

[0065] Step two: put 2000 g of dry wolframite beneficiation tailings into a blender;

[0066] Step three: take 20 g of the stabilizer basic component A obtained in step one and add it to the blender in step two to mix and stir with the wolframite beneficiation tailings uniformly to obtain a mixture;

[0067] Step four: add 200 mL of a 0.2% sodium tripolyphosphate aqueous solution to the mixture obtained in step three to obtain a solidified and stabilized body;

[0068] Step five: cure the solidified and stabilized body for 24 hours;

[0069] Step six: store the solidified and stabilized body in the open air for 180 days;

[0070] Step seven: sample the solidified stable wolframite beneficiation tailings after curing, and conduct leaching toxicity test according to the standard requirements of "Solid Waste Leaching Toxicity Leaching Method Horizontal Oscillation Method" (HJ557-2010). The test results of curing time of 24 hours and open-air storage of 180 days are shown in Table 1.

[0071] After the base component A of the stabilizer of the present application is uniformly mixed with the wolframite beneficiation tailings, it is uniformly distributed in the tailings particles. After adding the water solution of the reinforcing component B (sodium tripolyphosphate), a multi-polar colloid such as aluminum hydroxide and iron hydroxide is formed. Through chemical reactions and physical effects such as adsorption, adhesion, bridging, and net trapping, arsenic ions and arsenic-containing substances, cadmium ions and cadmium-containing substances, etc. are polymerized, so that the heavy metal pollutants such as arsenic and cadmium cannot be precipitated in water, thereby playing a stabilizing and solidifying effect. At the same time, the multi-polar colloid such as aluminum hydroxide and iron hydroxide and the water-insoluble calcium carbonate and iron oxide in the stabilizer prevent the arsenic-containing minerals and cadmium-containing minerals in the tailings from being further oxidized to form easily water-soluble arsenic-containing substances and cadmium-containing substances. As can be seen from Table 1, compared with the control example without the stabilizer, due to the fine particle size, uniform distribution, and fast effect of the stabilizer of the present application, the concentrations of heavy metal pollutants such as arsenic and cadmium in the leaching solution after curing for 24 hours are lower than the limit values of the "Integrated Wastewater Discharge Standard" (GB8978-1996), and the solidification and stabilization effect of arsenic and cadmium pollutants is very obvious, and the solidification and stabilization effect does not decrease after open-air storage for 180 days. This further proves that the mechanism of the stabilizer of the present application for solidification and stabilization of heavy metal pollutants in wolframite beneficiation tailings is clear and the effect is outstanding.

[0072] Example 4

[0073] In order to illustrate the practical application effect of the present application, the heavy metal pollutants in a certain wolframite beneficiation tailings are solidified and stabilized by using the stabilizer and method according to the present application. The heavy metal content of the wolframite beneficiation tailings is arsenic 1349.38 mg / kg and cadmium 189.26 mg / kg.

[0074] In combination Figure 1 , the preparation of the stabilizer and the method for treating the wolframite beneficiation tailings in this example are as follows:

[0075] Step one: put 46 kg of polyaluminum ferric chloride, 45 kg of calcium hydroxide, 8.8 kg of calcium carbonate, and 0.2 kg of iron oxide into a ball mill according to the proportion for grinding, and pass them through a 200-mesh screen to obtain the base component A of the stabilizer.

[0076] Step two: take 5000 g of dry weight of the wolframite tailings and put them into a blender.

[0077] Step three: take 60 g of the base component A of the stabilizer obtained in step one and add it to the blender in step two and mix it with the wolframite beneficiation tailings uniformly.

[0078] Step four: 700 mL of 0.2% sodium tripolyphosphate aqueous solution is added to the mixture of the step three base component A and the wolframite beneficiation tailings;

[0079] Step five: the solidified and stabilized product is cured for 48 hours and exposed to the open air for 180 days.

[0080] Step six: the cured and stabilized wolframite beneficiation tailings after curing are sampled and subjected to leaching toxicity test according to the standard of "Solid Waste Leaching Toxicity Leaching Method Horizontal Oscillation Method" (HJ557-2010). The test results of the curing time of 24 hours and the open-air exposure of 180 days are shown in Table 1.

[0081] After the stabilizer base component A of the present application is uniformly mixed with the wolframite beneficiation tailings, it is uniformly distributed in the tailings particles. After the addition of the aqueous solution of the reinforcing component B (sodium tripolyphosphate), a multi-polar colloid such as aluminum hydroxide and iron hydroxide is formed. Through chemical reactions and physical effects such as adsorption, adhesion, bridging, and net capture, arsenic ions and arsenic-containing substances, cadmium ions and cadmium-containing substances, etc. are polymerized, so that the heavy metal pollutants such as arsenic and cadmium cannot be precipitated in water, thereby playing a stabilizing and solidifying role. At the same time, the multi-polar colloid such as aluminum hydroxide and iron hydroxide and the water-insoluble calcium carbonate and iron oxide in the stabilizer prevent the arsenic-containing minerals and cadmium-containing minerals in the tailings from being further oxidized to form easily water-soluble arsenic-containing substances and cadmium-containing substances. As can be seen from Table 1, compared with the control example without the stabilizer, due to the fine particle size, uniform distribution, and fast effect of the stabilizer of the present application, the concentrations of the heavy metal pollutants arsenic and cadmium in the leaching solution after curing for 24 hours are lower than the limit values of the "Sewage Comprehensive Discharge Standard" (GB8978-1996), and the solidification and stabilization effect of the arsenic and cadmium pollutants is very obvious, and the solidification and stabilization effect does not decrease after being exposed to the open air for 180 days. This further proves that the mechanism of the stabilizing agent of the present application for solidification and stabilization of the heavy metal pollutants in the wolframite beneficiation tailings is clear and the effect is outstanding.

[0082] Example 5

[0083] In order to illustrate the actual application effect of the present application, the heavy metal pollutants in a certain wolframite beneficiation tailings are solidified and stabilized according to the stabilizer and the use method of the present application. The heavy metal content of the certain wolframite beneficiation tailings is arsenic 1349.38 mg / kg and cadmium 189.26 mg / kg.

[0084] In combination Figure 1 , the preparation of the solidification agent and the method for treating the wolframite beneficiation tailings in this example are as follows:

[0085] Step one: 49 kg of polyaluminum ferric chloride, 49 kg of calcium hydroxide, 1.8 kg of calcium carbonate, and 0.2 kg of iron oxide are put into a ball mill for grinding, and all pass through a 200-mesh screen to obtain the stabilizer base component A:

[0086] Step two: take 10000g of a certain wolframite beneficiation tailings with dry weight and put it into a blender;

[0087] Step three: take 250g of the stabilizer base component A obtained in step one and add it into the blender in step two and mix it with the wolframite beneficiation tailings evenly;

[0088] Step four: add 1500mL of 0.1% sodium tripolyphosphate aqueous solution into the material obtained in step three after the base component A and the wolframite beneficiation tailings are mixed evenly;

[0089] Step five: maintain the solidified and stabilized product, and the maintenance time is 48 hours; then store it in the open air for 180 days;

[0090] Step six: sample the solidified and stabilized wolframite beneficiation tailings after maintenance, and conduct the leaching toxicity test according to the standard requirements of the “Solid Waste Leaching Toxicity Leaching Method Horizontal Oscillation Method” (HJ557-2010). The test results of the maintenance time of 24 hours and the open-air storage time of 180 days are shown in Table 1.

[0091] After the stabilizer base component A of the present application is mixed evenly with the wolframite beneficiation tailings, it is evenly distributed in the tailings particles. After the addition of the aqueous solution of the reinforcing component B (sodium tripolyphosphate), a multi-polar colloid such as aluminum hydroxide and iron hydroxide is formed. Through chemical reactions and physical effects such as adsorption, adhesion, bridging, and net capture, arsenic ions and arsenic-containing substances, cadmium ions and cadmium-containing substances, etc. are polymerized, so that the heavy metal pollutants such as arsenic and cadmium cannot be precipitated in water, and the stabilizing and solidifying effects are achieved. At the same time, the multi-polar colloid such as aluminum hydroxide and iron hydroxide and the water-insoluble calcium carbonate and iron oxide in the stabilizer prevent the arsenic-containing minerals and cadmium-containing minerals in the tailings from being further oxidized to form easily water-soluble arsenic-containing substances and cadmium-containing substances. As can be seen from Table 1, compared with the control example without the stabilizer, due to the fine particle size, uniform distribution, and fast effect of the stabilizer of the present application, the concentration of heavy metal arsenic and cadmium pollutants in the leaching solution is lower than the limit value of the “Sewage Comprehensive Discharge Standard” (GB8978-1996) after 24 hours of maintenance, and the solidification and stabilization effect of arsenic and cadmium pollutants is very obvious. The solidification and stabilization effect does not decrease after 180 days of open-air storage, indicating that the heavy metals in the tailings do not resolubilize, and the effect is stable. It further proves that the mechanism of the stabilizing agent of the present application for solidification and stabilization of heavy metal pollutants in wolframite beneficiation tailings is clear and the effect is outstanding.

[0092] Table 1: Solidification and stabilization test results of wolframite beneficiation tailings (method HJ557-2010)

[0093]

[0094] Note: (unit: mg / L, pH is dimensionless).

[0095] The above data and table show that when the heavy metal pollutants are one or more of arsenic and cadmium, the content of arsenic in the tailings is ≤15000 mg / kg, and the stabilizer particles are less than 200 mesh, the tailings can be better mixed and uniformly distributed between various minerals, under the action of the reinforcing component and water, the polyaluminum ferric chloride and calcium hydroxide hydrolyze and immediately react with heavy metals such as cadmium and arsenic to generate Cd4Al2O6Cl2·10H2O and Al2(AsO4)(OH)3·3H2O, etc. Details are shown in Figure 2 、 Figure 3 Example. At the same time, complex agglomeration, polymerization, physical adsorption and other physicochemical mineralization effects are generated, such as Figure 4 Heavy metals such as arsenic, copper and lead in the tailings are combined with iron and aluminum to form polynuclear polymers and are consolidated together, greatly reducing the toxicity and leaching rate of the heavy metals; sodium tripolyphosphate is selected as a reinforcing agent to synergistically act with the basic component A, so that the heavy metal minerals generated in the solidification and stabilization process are more stable. As can be seen from the examples (Table 1), the heavy metal pollutants leached after stabilization are far lower than the limit value of the “Integrated Wastewater Discharge Standard” (GB8978-1996), and the arsenic and cadmium are reduced from 10.15 mg / L and 0.81 mg / L before solidification and stabilization to 0.11 mg / L and 0.0041 mg / L, respectively, and the solidification rate reaches 98.91% and 99.49%, respectively. The black tungsten ore dressing tailings are changed from Class II solid waste to Class I solid waste after stabilization, and the environmental pollution risk is greatly reduced. It can be seen that the heavy metal pollutant stabilizer for black tungsten ore dressing tailings of the present application is a heavy metal solidification and stabilization agent with fast effect and good effect.

[0096] The above examples are only preferred examples for fully illustrating the present application, and the protection scope of the present application is not limited thereto. Any equivalent replacement or transformation made by those skilled in the art on the basis of the present application is within the protection scope of the present application. The protection scope of the present application is subject to the claims.

Claims

1. A heavy metal contaminant stabilizer for wolframite beneficiation tailings, characterized by: The total mass is 100%, including base component A and reinforcing component B; the base component A is: polymeric aluminum ferric chloride, calcium hydroxide, calcium carbonate, iron oxide; The polymeric aluminum ferric chloride is an industrial product, wherein the alumina is ≥26%, the iron oxide is 3% to 6%, the basicity is ≥65%, and the arsenic is ≤0.0003%; The calcium hydroxide, calcium carbonate, and iron oxide are industrial products; The reinforcing component B is sodium tripolyphosphate, which is an industrial product and is used in the form of an aqueous solution; When the heavy metal content of the wolframite beneficiation tailings is arsenic 1349.38 mg / kg and cadmium 189.26 mg / kg, the use method of the stabilizer is as follows: Step 1: Put 49 kg of polymeric aluminum ferric chloride, 49 kg of calcium hydroxide, 1.8 kg of calcium carbonate, and 0.2 kg of iron oxide into a ball mill for grinding, all pass through a 200-mesh screen, and are activated to obtain the base component A; Step 2: Put 500 g of a certain wolframite beneficiation tailings by dry weight into a blender; Step 3: Take 10 g of the base component A obtained in step 1 and add it to the blender in step 2, and mix and stir the wolframite beneficiation tailings uniformly to obtain a mixture; Step 4: Add 50 mL of a 0.3% sodium tripolyphosphate aqueous solution to the mixture obtained in step 3 to form a solidified and stabilized body; the water content of the solidified and stabilized body is controlled to be 20% to 30%, and the pH value is 9; Step 5: Cure the solidified and stabilized body for 24 hours; Step 6: Leave the solidified and stabilized body in the open air for 180 days, and the effect is stable.

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