Fluorite beneficiation process for high-calcium scheelite tailings

Abstract

The invention relates to the technical field of fluorite beneficiation, in particular to a fluorite beneficiation process for high-calcium scheelite tailings. The beneficiation process comprises the following steps that after high-calcium scheelite tailings containing fluorite resources, water and a beneficiation reagent are mixed, ore grinding is conducted, and ore pulp is obtained; the beneficiation reagent comprises oleic acid, water glass and an inhibitor. The ore pulp and a roughing agent are mixed for roughing, and roughing concentrate is obtained; the roughing agent comprises oleic acid and water glass; in the concentration process, the roughing concentrate is subjected to concentration in the presence of a concentration agent, and fluorite concentrate powder is obtained; the selected medicament comprises an inhibitor. According to the beneficiation technology, the problems that in the process of extracting fluorite from fluorite resource-containing high-calcium scheelite tailings, effective separation of fluorite and calcite is difficult to achieve, and the grade and the recovery rate of fluorite are low are solved.

Description

Technical Field

[0001] The invention relates to the technical field of fluorite beneficiation, and in particular to a fluorite beneficiation process of high-calcium scheelite tailings containing fluorite resources. Background Art

[0002] Fluorite, also known as fluorspar, is a mineral widely found in nature. Its main component is calcium fluoride. It is a key mineral resource for the extraction of fluorine and plays an important role in many industrial fields. In the metallurgical industry, fluorite is often used as a solvent and slag remover in the production of iron, steel and ferroalloys due to its low melting point. It can significantly reduce the melting point of slag and improve smelting efficiency. At the same time, fluorite is an important component of cryolite, a key raw material in the aluminum industry, and is valued in the fields of optics and art for its unique optical properties. In the chemical industry, fluorite is the basic raw material for the manufacture of hydrofluoric acid, which has promoted the development of pesticides, medicine, electronics and other fields. Therefore, with the growth of industrial demand, the rational development and utilization of fluorite resources is particularly important.

[0003] The high-calcium scheelite tailings after the flotation of scheelite are an important source of fluorite extraction. They not only contain a large amount of fluorite, but also a high content of calcite. The CaF2 and CaCO3 in their chemical composition represent the main components of fluorite and calcite, respectively. Usually, the high-calcium scheelite tailings contain CaF2≤25% and CaCO3≥16%. However, due to the high content of impurities such as CaCO3 contained in the high-calcium scheelite tailings, and the similar calcium ion active sites on the surfaces of the fluorite and calcite contained, their surface properties are similar, which increases the difficulty of the two in the flotation separation process. In addition, the particle size of the high-calcium scheelite tailings is small, and there are reagent residues on the surface. These factors further increase the difficulty of separating fluorite and calcite. Therefore, it is often difficult to achieve the ideal separation effect for fluorite flotation of high-calcium scheelite tailings using the traditional flotation fluorite method, and the separated fluorite has a low grade, a low recovery rate, and there is a serious waste of resources. Summary of the invention

[0004] In order to solve the problems that the traditional fluorite flotation method has poor separation effect in the process of fluorite flotation of high-calcium scheelite tailings, and the separated fluorite has low grade and low recovery rate, the purpose of the present invention is to provide a fluorite beneficiation process for high-calcium scheelite tailings.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows.

[0006] The present invention provides a high-calcium scheelite tailings fluorite beneficiation process, including a grinding process, a roughing process, a concentrating process and a scavenging process. The specific process method includes the following steps:

[0007] Grinding process: After mixing high-calcium scheelite tailings, water and mineral processing agents, grind them to obtain grinding slurry; based on each ton of high-calcium scheelite tailings, the mineral processing agents include 100g / t~120g / t of oleic acid, 280g / t~300g / t of water glass, 300g / t~320g / t of sulfuric acid and 60g / t~80g / t of inhibitors.

[0008] Roughing process: After the grinding slurry is mixed with the roughing agent, roughing is carried out to obtain roughing concentrate and roughing tailings; based on each ton of high-calcium scheelite tailings, the roughing agent includes 150g / t to 250g / t of oleic acid and 5g / t to 15g / t of water glass.

[0009] Concentration process: The rough concentrate is concentrated multiple times in the presence of a concentrating agent to obtain fluorite concentrate powder; the concentrating agent includes an inhibitor, and the amount of the inhibitor added each time is 60g / t to 100g / t per ton of high-calcium scheelite tailings.

[0010] The inhibitor is obtained by mixing the following raw materials in parts by weight:

[0011] 4-5 parts of sodium hexametaphosphate, 10-12 parts of sodium humate, 20-25 parts of modified starch, 30-35 parts of synthetic tannin S-804 or natural tannin, 15-20 parts of calcium lignin sulfonate and 4-5 parts of sodium sulfite.

[0012] Since the particle size of the high-calcium scheelite tailings after the flotation of scheelite is relatively small, and there are residual reagents on the surface, and the residual reagents on the surface will increase the difficulty of separating fluorite and calcite, therefore, the mineral processing technology of the present invention first grinds the high-calcium scheelite tailings containing fluorite resources, and removes the residual reagents on the surface of the high-calcium scheelite tailings while further improving the fineness of the slurry to generate a new mineral surface, and the newly generated mineral surface is re-contacted with the mineral processing reagent to improve the mineral processing recovery rate and product quality. Afterwards, oleic acid and water glass are used to perform roughing of the ground slurry at room temperature to separate the roughing foam on the upper layer and the roughing tailings on the lower layer. Finally, the roughing foam is refined with an inhibitor to further separate the refined foam on the upper layer to obtain stone concentrate powder.

[0013] The grinding process of the present invention achieves effective separation of fluorite minerals and gangue minerals during flotation through the mutual combination of various steps, while improving the concentrate grade and product recovery rate, reducing the cost of mineral processing, and improving the economic benefits of mineral processing, thereby solving the problems of poor separation effect, low grade and low recovery rate of separated fluorite in the fluorite flotation process of high-calcium scheelite tailings by the traditional fluorite flotation method.

[0014] The ore dressing agent of the present invention comprises oleic acid, water glass and an inhibitor, and the ore dressing recovery rate and product quality are improved by the combination of the components. The roughing agent of the present invention comprises oleic acid and water glass, and the separation effect is further improved by the combination of the components. The concentrating agent of the present invention comprises an inhibitor, and the ore dressing recovery rate and product quality are further improved by the inhibitor.

[0015] Oleic acid is used as a collector for flotation of calcium fluoride; since fluorite and calcite have similar calcium ion active sites on their surfaces, it is difficult to separate the two during flotation, and the difference in floatability between the two is small. The present invention uses pure oleic acid, which has a relatively low cost compared to modified oleic acid.

[0016] Water glass plays an inhibitory and activating role. Acidic water glass has a good inhibitory effect and can effectively remove the residual reagents on the surface of the mineral. For example, sulfide ores are mainly floated by xanthate and black medicine. After flotation, xanthate and black medicine exist on the surface, and the surface reagents must be removed under acidic conditions. During the use of the water glass of the present invention, it needs to be configured into an aqueous solution to generate water glass with a certain modulus to improve fluidity. Water glass not only has an inhibitory effect, but also has an activating effect. If the amount of water glass added is too little, impurities cannot be removed; if the amount of water glass added is too much, the recovery rate of fluorite concentrate powder is affected; therefore, the amount of water glass added needs to be strictly controlled.

[0017] Sulfuric acid, as a pH adjuster and activator, mainly plays an activating role. The reaction of sulfuric acid and water glass will form acidic water glass, which improves the inhibitory effect. During use, 98% sulfuric acid needs to be configured into dilute sulfuric acid with a concentration of 15% to 30%. By controlling the amount of dilute sulfuric acid, the reaction pH is adjusted to 6 to 7. The high-calcium scheelite tailings of the present invention need to be ground and floated in a weakly acidic environment.

[0018] The inhibitor plays a role in inhibiting the floating of impurities and can remove impurities in the flotation process. The inhibitor of the present invention is configured into an aqueous solution of a certain concentration during use, with a concentration of 8% to 10%, to improve fluidity and facilitate addition. The inhibitory effect described in the present invention is mainly aimed at the inhibitory effect on calcium impurities in the ore. Therefore, in the initial stage of flotation, the inhibitory effect cannot be too strong, otherwise the fluorite that needs to be floated will be suppressed, or a part of it will be suppressed. The inhibitor of the present invention can be combined with water glass to remove impurities in the flotation process or prevent impurities from floating up.

[0019] Preferably, the high-calcium scheelite tailings are high-calcium scheelite tailings with CaF2≤25% and CaCO3≥16%. The high-calcium scheelite tailings described in the present invention are high-calcium scheelite tailings containing fluorite resources. The process of the present invention is used to effectively separate fluorite and calcite, and obtain acid-grade fluorite concentrate powder containing CaCO3≤0.8%, CaF2≥96%, and SiO2≤1.5%. The fluorite concentrate powder has high indicators and good quality, and solves the problem of difficulty in effectively separating fluorite and calcite in the process of extracting fluorite from high-calcium scheelite tailings, resulting in a low recovery rate of fluorite.

[0020] Preferably, the mass of -0.074 mm ore particles in the grinding slurry accounts for 82% to 85% of the total mass of high-calcium scheelite tailings. The present invention mainly grinds high-calcium scheelite tailings, and helps to improve the separation effect of fluorite and calcite on the basis of reducing the fineness of the ore particles in the grinding slurry to -0.074 mm ore particles accounting for 82% to 85%. The present invention improves the grinding efficiency by reasonably controlling the flotation particle size requirements.

[0021] Preferably, before grinding, the method further comprises: adjusting the pH of the grinding system to 6-7.

[0022] Preferably, the grinding process includes a first-stage grinding process and a second-stage grinding process.

[0023] The first stage grinding process is to mix the high calcium scheelite tailings with water, add beneficiation agents, and adjust the pH to 6-7, and then perform the first stage grinding until the high calcium scheelite tailings are ground to -0.074mm ore particles accounting for 60% to 65% of the total mass of the high calcium scheelite tailings; then form a closed circuit grinding with the spiral classifier, and the overflow enters the second stage grinding process.

[0024] The two-stage grinding process is to use a vertical mechanical slurry pump and a hydrocyclone in parallel to form a two-stage closed-circuit grinding operation; until the high-calcium scheelite tailings are ground to -0.074mm ore particles accounting for 82% to 85% of the total mass of the high-calcium scheelite tailings, to obtain a two-stage slurry.

[0025] In the present invention, the first-stage cyclone classification is achieved by the first hydrocyclone; the second-stage cyclone classification is achieved by the second hydrocyclone. Both the first-stage grinding and the second-stage grinding are achieved by a ball mill. The present invention uses multi-stage grinding and combines a hydrocyclone during the grinding process to timely sort out coarse and fine particle size minerals, reduce over-grinding of fine mineral particles, prevent mudification, and help improve the quality of mineral processing. The present invention combines the first-stage grinding with the second-stage grinding, which not only helps to improve the dissociation degree of the selected ore, but also helps to improve the quality of mineral processing.

[0026] Preferably, the one-stage grinding process uses a steel segment of ∮45mm×50mm as a grinding medium, or a steel segment of ∮45mm×50mm mixed with a steel segment of ∮25mm×30mm as a grinding medium; the two-stage grinding process uses a steel segment of ∮25mm×30mm as a grinding medium. Specifically, when the one-stage grinding process uses a steel segment of ∮45mm×50mm mixed with a steel segment of ∮25mm×30mm as a grinding medium, the mass percentage of the steel segment of ∮45mm×50mm in the grinding medium is 60% to 70%. The present invention uses steel segments of different sizes as grinding media to match different grinding processes, thereby separating minerals of -0.074mm ore particles step by step to avoid over-grinding of fine mineral particles and mudification. Because fluorite is relatively brittle and has a molar hardness of 4, it is more suitable for steel segment grinding.

[0027] Preferably, the overflow slurry concentration of the first-stage grinding process is 30% to 35%; the overflow slurry concentration of the second-stage grinding process is 25% to 30%.

[0028] Preferably, the beneficiation process is to beneficiate the rougher concentrate 6 to 7 times, and beneficiation reagents are added in the first 5 beneficiations.

[0029] Preferably, the beneficiation process includes a first beneficiation process, a second beneficiation process, a third beneficiation process, a fourth beneficiation process, a fifth beneficiation process and a sixth beneficiation process; based on each ton of high-calcium scheelite tailings, the first beneficiation process is to add 60g / t to 100g / t of inhibitors to the rougher concentrate; the second beneficiation process to the fifth beneficiation process are all to add 60g / t to 100g / t of inhibitors to the beneficiated concentrate obtained in the previous beneficiation process; and as the number of beneficiation times increases, the amount of inhibitor added gradually decreases.

[0030] Preferably, based on the calculation of each ton of high-calcium scheelite tailings, the first concentration process is to add 95g / t to 100g / t of inhibitor to the roughing concentrate, perform the first concentration, and obtain the first concentrated concentrate and the first concentrated middlings; a part of the first concentrated middlings is transferred to a first grinding process, and a part is transferred to a scavenging process; the second concentration process is to add 75g / t to 80g / t of inhibitor to the first concentrated concentrate, perform the second concentration, and obtain the second concentrated concentrate and the second concentrated middlings; the second concentrated middlings are transferred to the first concentration process; the third concentration process is to add 75g / t to 80g / t of inhibitor to the second concentrated concentrate, perform the third concentration, and obtain the third concentrated concentrate and the third concentrated middlings. The intermediate ore is transferred to the second concentration process; the fourth concentration process is to add 75g / t~80g / t of inhibitor to the third concentrated concentrate, and carry out the fourth concentration to obtain the fourth concentrated concentrate and the fourth concentrated intermediate ore; the fourth concentrated intermediate ore is transferred to the third concentration process; the fifth concentration process is to add 60g / t~65g / t of inhibitor to the fourth concentrated concentrate, and carry out the fifth concentration to obtain the fifth concentrated concentrate and the fifth concentrated intermediate ore; the fifth concentrated intermediate ore is transferred to the fourth concentration process; the sixth concentration process is to carry out the sixth concentration on the fifth concentrated concentrate, and carry out the sixth concentration to obtain fluorite concentrate powder and the sixth concentrated intermediate ore; the sixth concentrated intermediate ore is transferred to the fifth concentration process.

[0031] Part of the first concentrated ore is transferred to the first grinding process; the rest of the first concentrated ore is transferred to the first scavenging process of the scavenging process. The main purpose of transferring part of the first concentrated ore to the first grinding process is to increase the concentration of the flotation pulp in the roughing process, thereby helping to reduce the dosage of the roughing collector oleic acid. At the same time, the concentrations of water glass, sulfuric acid and inhibitors are slightly increased.

[0032] Preferably, after the roughing process, a scavenging process is also included, in which the roughing tailings are scavenged; the number of scavenging is 1 to 3 times; and a scavenging agent is added during the first scavenging, and the scavenging agent is oleic acid. The amount of oleic acid added is 10 g / t to 20 g / t per ton of high-calcium scheelite tailings.

[0033] Preferably, the scavenging process includes a first scavenging step, a second scavenging step and a third scavenging step; the first scavenging step is to mix the roughing tailings and a part of the first concentrated ore and oleic acid and then perform the first scavenging to obtain the first scavenging foam and the first scavenging tailings; the first scavenging foam is transferred to the roughing step; the second scavenging process is to perform a second scavenging on the first scavenging tailings to obtain the second scavenging foam and the second scavenging tailings; the second scavenging foam is transferred to the first scavenging step; the third scavenging process is to perform a third scavenging on the second scavenging tailings to obtain the third scavenging concentrate and the third scavenging tailings; the third scavenging concentrate is transferred to the second scavenging process, and the third scavenging tailings are discarded at the same time.

[0034] Beneficial effects of the present invention:

[0035] 1. The present invention removes the residual reagents on the surface of high-calcium scheelite tailings while further reducing the fineness of the ore pulp through grinding treatment to generate a new mineral surface, and the newly generated mineral surface is re-contacted with the dressing reagent to improve the dressing recovery rate and product quality. Afterwards, oleic acid and water glass are used to perform rough separation on the ground slurry at room temperature to separate the roughing foam on the upper layer and the roughing tailings on the lower layer. Finally, the roughing foam is finely selected using an inhibitor to further separate the fine foam on the upper layer to obtain stone concentrate powder. The grinding process of the present invention, through the mutual combination of various steps, can effectively separate fluorite minerals from gangue minerals during the flotation process, improve the concentrate grade and product recovery rate, reduce the dressing cost, and improve the economic benefits of the dressing process, solving the problem that the traditional flotation fluorite method has poor separation effect in the fluorite flotation process of high-calcium scheelite tailings, and the separated fluorite has a low grade and low recovery rate.

[0036] 2. The present invention effectively and reasonably controls the grinding particle size, and controls the product under the -0.074mm sieve to 82% to 85% when entering the flotation, so that the fluorite mineral and the gangue mineral can be effectively separated during the flotation process, the concentrate grade and product recovery rate can be improved, the mineral processing cost can be reduced, and the economic benefit of mineral processing can be improved.

[0037] 3. The flotation process of the present invention adopts a fluorite flotation process of one roughing selection, three scavenging selections and six cleaning selections, and obtains acid-grade fluorite concentrate powder containing CaCO3≤0.8%, CaF2≥96%, and SiO2≤1.5% from high-calcium scheelite tailings with CaCO3≥16% and CaF2≤25%. The fluorite concentrate powder has high indicators and good quality, and solves the problem of low fluorite recovery rate caused by difficulty in effectively separating fluorite and calcite in the process of extracting fluorite from high-calcium scheelite tailings.

[0038] 4. The process of the present invention can improve the fluorite recovery rate to more than 82%. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 A flow chart of a high-calcium scheelite tailings fluorite beneficiation process provided in one embodiment of the present invention. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0041] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without making any creative work shall fall within the scope of protection of the present invention.

[0042] In the present invention, fluorite, also known as fluorspar, is mainly composed of calcium fluoride with a chemical formula of CaF2. Calcite is a carbonate mineral, and its main component is calcium carbonate with a chemical formula of CaCO3.

[0043] The present invention mainly provides a mineral processing technology for flotation of high-calcium scheelite tailings containing CaCO3≥16% and CaF2≤25% to recover fluorite concentrate powder.

[0044] The high calcium scheelite tailings containing CaF2≤25% and CaCO3≥16% are mainly composed of CaF2, CaCO3 and SiO2, among which CaF2 is the main component of fluorite and CaCO3 is the main component of calcite. Since the high calcium scheelite tailings contain a lot of impurities such as CaCO3, and the fluorite and calcite contained in them have similar calcium ion active sites on their surfaces, their surface properties are similar, which increases the difficulty of the two in the flotation separation process. This is especially obvious when using conventional fatty acid collectors. Conventional fatty acid collectors have good collection effects on fluorite and calcite. Therefore, it is difficult to achieve effective separation of fluorite and calcite using traditional fluorite flotation processes. In addition, the high calcium scheelite tailings are tailings after the flotation of scheelite. Due to the small particle size and the presence of reagents on its surface, this will further increase the difficulty of flotation separation.

[0045] Based on this, the present invention mainly realizes the grinding particle size control of high-calcium scheelite tailings by two-stage closed-circuit grinding process, and the -0.074mm undersize product accounts for more than 85% of the high-calcium scheelite tailings raw materials. Sulfuric acid is used as pH adjuster and inhibitor, water glass is used as activator and inhibitor, oleic acid is used as frother and collector, MCA-1 is used as inhibitor, and in two-stage closed-circuit grinding operation, the slurry and the reagent are fully stirred and mineralized, and then roughing is carried out, and then the foam after roughing is fined for six to seven times to obtain fluorite concentrate powder; MCA-1 is added during the first five fines.

[0046] The process method of the invention realizes the stable operation of the flotation process, and effectively and reasonably controls the grinding particle size of the -0.074 mm undersize product to 82% to 85% at the time of selection through two-stage closed-circuit grinding, so that the fluorite mineral and the gangue mineral are effectively separated during the flotation process, the concentrate grade and product recovery rate are improved, the mineral processing cost is reduced, and the economic benefit of mineral processing is improved.

[0047] The flotation process of the present invention adopts a fluorite flotation process of one roughing selection, three scavenging selections and six cleaning selections to obtain acid-grade fluorite concentrate powder containing CaCO3≤0.8%, CaF2≥96% and SiO2≤1.2% from high-calcium scheelite tailings with CaCO3≥16% and CaF2≤25%.

[0048] The technical solution of the present invention is further described below by means of specific examples. In the following examples, the methods described are conventional methods unless otherwise specified; the reagents and materials described are commercially available unless otherwise specified.

[0049] In the following examples, unless otherwise specified, % refers to mass percentage.

[0050] In the following examples, the inhibitor is an MCA-1 inhibitor, referred to as MCA-1.

[0051] In the following embodiments, the high-calcium scheelite tailings are selected from high-calcium scheelite tailings with CaCO3≥16% and CaF2≤25%.

[0052] In the following embodiments, the normal temperature condition is: 20-30° C. 200 mesh, i.e. 0.074 mm.

[0053] In the following embodiments, the sulfuric acid is concentrated sulfuric acid with a concentration of 93% to 98% by mass; the dilute sulfuric acid is dilute sulfuric acid with a concentration of 15% to 30%.

[0054] In the following embodiments, the inhibitor is composed of sodium hexametaphosphate, sodium humate, modified starch, synthetic tannin S-804 or natural tannin, calcium lignin sulfonate and sodium sulfite; after dissolution, it mainly plays the role of reducing calcium carbonate. The inhibitor is recorded as MCA-1. MCA-1 is prepared into an aqueous solution with a concentration of 2wt% to 8wt%.

[0055] In the following examples, sodium hexametaphosphate was purchased from Suzhou Yiju Chemical Co., Ltd. Sodium humate was purchased from Jinan Haoyunlai Chemical Technology Co., Ltd. Modified starch was purchased from Shandong Pingju Biotechnology Co., Ltd. Natural tannin extract was purchased from Henan Hongshuo Chemical Products Co., Ltd. Calcium lignin sulfonate was purchased from Hubei Changyao Biotechnology Co., Ltd. Oleic acid and water glass were purchased from Jiangsu Bosite Chemical Technology Co., Ltd.

[0056] Synthetic tannin is a condensate of p-hydroxybenzenesulfonic acid or naphthalenesulfonic acid and formaldehyde or other aldehydes. The synthetic tannin used in the present invention is synthetic tannin S-804, with the structural formula: n=3~5.

[0057] The mineral processing reagent, roughing reagent, scavenging reagent and concentrating reagent described in the present invention, wherein each component is added through a corresponding pipeline, therefore, each raw material component needs to be configured into a solution of corresponding concentration before use. The concentration of the solution is mainly determined by not blocking the pipeline and satisfying the volume of the corresponding reaction container. If the solution concentration is too high, insoluble matter may appear and block the pipeline. If the concentration is too low, too much water will be added, which will make the overall volume too large, resulting in the reaction container being insufficient to hold.

[0058] Example 1

[0059] like Figure 1 , a high calcium scheelite tailings fluorite beneficiation process, comprising the following steps:

[0060] Step 1, raw material pretreatment:

[0061] The fluorite-containing tailings produced during the flotation of scheelite are naturally dried and evenly mixed to obtain high-calcium scheelite tailings with CaCO316% and CaF225%.

[0062] Step 2, primary grinding:

[0063] The high calcium scheelite tailings obtained by pretreatment are used as raw materials for fluorite flotation and added to a first-stage ball mill. At the same time, a beneficiation agent is added to the feed port of the first-stage ball mill. The beneficiation agent is 120g of oleic acid, 300g of water glass, 320g of sulfuric acid and 80g of MCA-1 per ton of high calcium scheelite tailings. Among them, MCA-1 is obtained by mixing 5 parts of sodium hexametaphosphate, 10 parts of sodium humate, 25 parts of modified starch, 435 parts of synthetic tannin S-80, 20 parts of calcium lignin sulfonate and 5 parts of sodium sulfite. Before adding, the Baume concentration of water glass is adjusted to 12%, the Baume concentration of sulfuric acid is adjusted to 18%, and the mass percentage concentration of MCA-1 is adjusted to 8%.

[0064] Then, at room temperature, adjust the pH to 6-7 and perform a first-stage grinding. During the first-stage grinding process, a ball mill is used for grinding, and a spiral classifier is used for classification. The overflow pulp concentration of the first-stage grinding is 30%-35%. After that, the slurry of the first-stage grinding is transported to the first hydrocyclone through the first vertical mechanical mortar pump, and the first hydrocyclone is used for classification, so that the overflow product with a particle size of -0.074mm reaches more than 60wt% of the raw material. After classification by the first hydrocyclone, a bottom sand and an upstream slurry are obtained. The first slurry enters the slurry box.

[0065] In the first stage of grinding, the first stage ball mill adopts ∮2445 wet grid ball mill.

[0066] The ∮45mm×50mm steel segment is used as a grinding medium, and together with the spiral classifier, it forms a closed-circuit grinding process for coarse and fine particle classification.

[0067] During the first grinding process, the high calcium scheelite tailings can produce new mineral surfaces, and the beneficiation reagents are in full contact with the new mineral surfaces and are wrapped on the surface of the high calcium scheelite tailings.

[0068] In the first stage grinding process, a part of the first concentrated ore is used as grinding water or adjustment water to input into the first stage ball mill, the purpose is to increase the concentration of the roughing ore pulp and improve the recovery rate; the increase in the concentration of the roughing ore pulp also helps to reduce the dosage of the collector oleic acid. At the same time, the concentrations of water glass, sulfuric acid and MCA-1 are slightly increased.

[0069] Step 3, Secondary Grinding:

[0070] The first-stage ore pulp is subjected to second-stage grinding by a second-stage ball mill, and the overflow ore pulp concentration of the second-stage grinding process is 25% to 30%. The overflow of the first-stage grinding classifier is transported to the first-stage hydrocyclone for classification through the first vertical mechanical mortar pump, and the underflow enters the second-stage ball mill. The overflow and the second-stage ball mill ore pulp enter the ore pulp box together, and are transported to the second-stage hydrocyclone for classification through the second vertical mechanical mortar pump. The underflow enters the second-stage ball mill, and the overflow enters the ore pulp stirring barrel, so that the overflow ore pulp of the second hydrocyclone has a particle size of -0.074mm and the undersize product reaches 85wt% of the raw material, and then enters the flotation stirring barrel for stirring to obtain the second-stage ore pulp after the second-stage grinding.

[0071] In the second stage grinding process, the second stage ball mill adopts ∮2460 wet grid ball mill.

[0072] The steel segment of ∮25mm×30mm is used as the second-stage grinding medium. The second vertical mechanical mortar pump adopts 4PN vertical mortar pump to transport slurry. The second vertical mechanical mortar pump and the second hydrocyclone form a two-stage closed-circuit grinding process for coarse and fine particle classification.

[0073] Two-stage grinding is a two-stage closed-circuit grinding operation formed by the parallel use of a vertical mechanical slurry pump and a hydrocyclone. The purpose is: first, to reasonably control the flotation particle size requirements and improve the grinding efficiency; second, the hydrocyclone can timely separate the coarse and fine particle sizes of minerals, reduce over-grinding of fine mineral particles, prevent mudification, and help improve the quality of mineral processing.

[0074] Step 4, rough selection:

[0075] After the second stage grinding, the second stage pulp is added with oleic acid 200g and water glass 15g per ton of high calcium scheelite tailings, and roughing is carried out at room temperature to obtain roughing foam and roughing tailings. The flotation machine used for roughing is XCF / KYF8 cubic aerated mechanical agitation flotation machine.

[0076] Step 5, Scan and select:

[0077] 13 g of oleic acid was added to the roughing tailings per ton of high-calcium scheelite tailings for scavenging; the scavenging was carried out three times, which were respectively recorded as scavenging one, scavenging two and scavenging three.

[0078] The first scavenging is to mix the roughing tailings and a part of the first concentrated ore with oleic acid and then carry out the first scavenging to obtain the first scavenging foam and the first scavenging tailings; the first scavenging foam is transferred to the roughing process.

[0079] The second sweeping is to carry out the second sweeping of the first sweeping tailings to obtain the second sweeping foam and the second sweeping tailings; the second sweeping foam is transferred to the first sweeping process.

[0080] The third scavenging is to carry out the third scavenging of the tailings of the second scavenging to obtain the third scavenging concentrate and the third scavenging tailings; the third scavenging concentrate is transferred to the second scavenging process, and the third scavenging tailings are discarded at the same time.

[0081] The flotation machine used for scavenging is XCF / KYF8 cubic aerated mechanical stirring flotation machine.

[0082] Step 6, Select:

[0083] The selection is carried out six times, which are recorded as one selection, two selections, three selections, four selections, five selections and six selections respectively.

[0084] The first selection, referred to as the first selection:

[0085] MCA-1100g is added as an inhibitor per ton of high-calcium scheelite tailings to the roughing froth for the first concentration to obtain the first concentration froth and the first concentration middlings. The flotation machine used for the first concentration is the XCF / KYF8 cubic aerated mechanical agitation flotation machine. Part of the first concentration middlings is transferred to the first grinding process; the rest of the first concentration middlings is transferred to the first scavenging process of the scavenging process. The transfer of part of the first concentration middlings to the first grinding process is mainly to increase the concentration of the flotation pulp of the roughing, thereby helping to reduce the dosage of the roughing collector oleic acid. At the same time, the concentrations of water glass, sulfuric acid and inhibitors are slightly increased.

[0086] The second selection, referred to as Erjing:

[0087] Add MCA-180g as an inhibitor per ton of high calcium scheelite tailings to the first concentration foam, and conduct the second concentration to obtain the second concentration foam and the second concentration middlings. The flotation machine used in the second concentration is the XCF / KYF4 cubic aerated mechanical agitation flotation machine. The second concentration middlings are transferred to the first concentration process.

[0088] The third selection, referred to as the three selections:

[0089] Add MCA-180g as an inhibitor per ton of high calcium scheelite tailings to the second concentration foam, and conduct the third concentration to obtain the third concentration foam and the third concentration middlings. The flotation machine used in the third concentration is XCF / KYF4 cubic aerated mechanical agitation flotation machine. The third concentration middlings are transferred to the second concentration process.

[0090] The fourth selection, referred to as the fourth selection:

[0091] Add MCA-180g as an inhibitor per ton of high calcium scheelite tailings to the third concentration foam, and carry out the fourth concentration to obtain the fourth concentration foam and the fourth concentration middlings. The flotation machine used in the fourth concentration is XCF / KYF4 cubic aerated mechanical agitation flotation machine. The fourth concentration middlings are transferred to the third concentration process.

[0092] The fifth selection, referred to as Wujing:

[0093] Add MCA-160g as an inhibitor per ton of high calcium scheelite tailings to the fourth concentration foam, and carry out the fifth concentration to obtain the fifth concentration foam and the fifth concentration middlings. The flotation machine used in the fifth concentration is XCF / KYF4 cubic aerated mechanical agitation flotation machine. The fifth concentration middlings are transferred to the fourth concentration process.

[0094] The Sixth Selection, referred to as the Sixth Selection:

[0095] The fifth selected foam is subjected to the sixth selection to obtain fluorite concentrate powder and the sixth selected middlings. The flotation machine used in the sixth selection is an XCF / KYF4 cubic aerated mechanical agitation flotation machine. The fluorite concentrate powder is an acid-grade fluorite concentrate powder containing CaCO3 0.2%, CaF2 98.5%, and SiO2 0.08%. The recovery rate of fluorite concentrate powder is 82%. The sixth selected middlings are transferred to the fifth selection process.

[0096] Example 2

[0097] A high-calcium scheelite tailings fluorite beneficiation process comprises the following steps:

[0098] Step 1, raw material pretreatment:

[0099] The fluorite-containing tailings produced during the flotation of scheelite are naturally dried and evenly mixed to obtain high-calcium scheelite tailings with CaCO3 20% and CaF2 22%.

[0100] Step 2, primary grinding:

[0101] The high calcium scheelite tailings obtained by pretreatment are used as raw materials for fluorite flotation and added to a first-stage ball mill. At the same time, a beneficiation agent is added to the feed port of the first-stage ball mill. The beneficiation agent is 120g of oleic acid, 300g of water glass, 320g of sulfuric acid and 80g of MCA-1 per ton of high calcium scheelite tailings. Among them, MCA-1 is obtained by mixing 5 parts of sodium hexametaphosphate, 10 parts of sodium humate, 25 parts of modified starch, 435 parts of synthetic tannin S-80, 20 parts of calcium lignin sulfonate and 5 parts of sodium sulfite. Before adding, the Baume concentration of water glass is adjusted to 12%, the Baume concentration of sulfuric acid is adjusted to 18%, and the mass percentage concentration of MCA-1 is adjusted to 8%.

[0102] Then, at room temperature, adjust the pH to 6-7 and perform a first-stage grinding. During the first-stage grinding process, a ball mill is used for grinding, and a spiral classifier is used for classification. The overflow pulp concentration of the first-stage grinding is 30%. After that, the pulp of the first-stage grinding is transported to the first hydrocyclone through the first vertical mechanical mortar pump, and the first hydrocyclone is used for classification, so that the overflow product with a particle size of -0.074mm reaches more than 60wt% of the raw material. After classification by the first hydrocyclone, a bottom sand and an upstream pulp are obtained. The first pulp enters the pulp box. The pulp concentration is the mass percentage of mineral particles in the pulp.

[0103] In the first stage of grinding, the first stage ball mill adopts ∮2445 wet grid ball mill.

[0104] The ∮45mm×50mm steel segment is used as a grinding medium and together with the spiral classifier, it forms a closed-circuit grinding process for coarse and fine particle classification.

[0105] During the first grinding process, the high calcium scheelite tailings can produce new mineral surfaces, and the beneficiation reagents are in full contact with the new mineral surfaces and are wrapped on the surface of the high calcium scheelite tailings.

[0106] In the first stage grinding process, a part of the first concentrated ore is used as grinding water or adjustment water to input into the first stage ball mill, the purpose is to increase the concentration of the roughing ore pulp and improve the recovery rate; the increase in the concentration of the roughing ore pulp also helps to reduce the dosage of the collector oleic acid. At the same time, the concentrations of water glass, sulfuric acid and MCA-1 are slightly increased.

[0107] Step 3, Secondary Grinding:

[0108] The first-stage ore pulp is subjected to second-stage grinding by a second-stage ball mill, and the overflow ore pulp concentration of the second-stage grinding process is 25% to 30%. The overflow of the first-stage grinding classifier is transported to the first-stage hydrocyclone for classification through the first vertical mechanical mortar pump, and the underflow enters the second-stage ball mill. The overflow and the second-stage ball mill ore pulp enter the ore pulp box together, and are transported to the second-stage hydrocyclone for classification through the second vertical mechanical mortar pump. The underflow enters the second-stage ball mill, and the overflow enters the ore pulp stirring barrel, so that the overflow ore pulp of the second hydrocyclone has a particle size of -0.074mm and the undersize product reaches 82wt% of the raw material, and then enters the flotation stirring barrel for stirring to obtain the second-stage ore pulp after the second-stage grinding.

[0109] Through the parallel use of vertical mechanical mortar pump and hydrocyclone, a two-stage closed-circuit grinding operation is formed; the purpose is: first, it can reasonably control the flotation particle size requirements and improve the grinding efficiency; second, the hydrocyclone can timely separate the coarse and fine particle size minerals, reduce the over-grinding of fine mineral particles, prevent mudification, and help improve the quality of mineral processing.

[0110] In the second stage grinding process, the second stage ball mill adopts ∮2460 wet grid ball mill.

[0111] The steel segment of ∮25mm×30mm is used as the second-stage grinding medium. The second vertical mechanical mortar pump adopts 4PN vertical mortar pump to transport slurry. The second vertical mechanical mortar pump and the second hydrocyclone form a two-stage closed-circuit grinding process for coarse and fine particle classification.

[0112] The two-stage grinding is a two-stage closed-circuit grinding operation formed by the parallel use of a vertical mechanical slurry pump and a hydrocyclone. The purpose is: first, to reasonably control the flotation particle size requirements and improve the mineral processing efficiency; second, the hydrocyclone can timely separate the coarse and fine particle sizes of minerals, reduce the over-grinding of fine minerals, prevent mudification, and help improve the mineral processing quality.

[0113] Step 4, rough selection:

[0114] After the second stage grinding, the pulp is added with 20g oleic acid and 10g water glass per ton of high calcium scheelite tailings, and roughing is carried out at room temperature to obtain roughing foam and roughing tailings. The flotation machine used for roughing is XCF / KYF8 cubic aerated mechanical agitation flotation machine. The overflow pulp concentration of roughing is 25wt% to 30wt%.

[0115] Step 5, Scan and select:

[0116] Add 10g of oleic acid per ton of high calcium scheelite tailings to the rougher tailings for scavenging; the scavenging is performed three times, which are recorded as scavenging one, scavenging two and scavenging three. Scavenging one is to mix the rougher tailings and the first concentrated ore with oleic acid and then scavenging for the first time to obtain the first scavenging foam and the first scavenging tailings; the first scavenging foam is transferred to the rougher process.

[0117] The second sweeping is to carry out the second sweeping of the first sweeping tailings to obtain the second sweeping foam and the second sweeping tailings; the second sweeping foam is transferred to the first sweeping process.

[0118] The third scavenging is to carry out the third scavenging of the tailings of the second scavenging to obtain the third scavenging concentrate and the third scavenging tailings; the third scavenging concentrate is transferred to the second scavenging process, and the third scavenging tailings are discarded at the same time.

[0119] The flotation machine used for scavenging is XCF / KYF8 cubic aerated mechanical stirring flotation machine.

[0120] Step 6, Select:

[0121] The selection is carried out six times, which are recorded as one selection, two selections, three selections, four selections, five selections and six selections respectively.

[0122] The first selection, referred to as the first selection:

[0123] MCA-1100g is added as an inhibitor per ton of high-calcium scheelite tailings to the roughing froth for the first concentration to obtain the first concentration froth and the first concentration middlings. The flotation machine used for the first concentration is the XCF / KYF8 cubic aerated mechanical agitation flotation machine. Part of the first concentration middlings is transferred to the first grinding process; the rest of the first concentration middlings is transferred to the first scavenging process of the scavenging process. The transfer of part of the first concentration middlings to the first grinding process is mainly to increase the concentration of the flotation pulp of the roughing, thereby helping to reduce the dosage of the roughing collector oleic acid. At the same time, the concentrations of water glass, sulfuric acid and inhibitors are slightly increased.

[0124] The second selection, referred to as Erjing:

[0125] Add MCA-180g as an inhibitor per ton of high calcium scheelite tailings to the first concentration foam, and conduct the second concentration to obtain the second concentration foam and the second concentration middlings. The flotation machine used in the second concentration is the XCF / KYF4 cubic aerated mechanical agitation flotation machine. The second concentration middlings are transferred to the first concentration process.

[0126] The third selection, referred to as the three selections:

[0127] Add MCA-180g as an inhibitor per ton of high calcium scheelite tailings to the second concentration foam, and conduct the third concentration to obtain the third concentration foam and the third concentration middlings. The flotation machine used in the third concentration is XCF / KYF4 cubic aerated mechanical agitation flotation machine. The third concentration middlings are transferred to the second concentration process.

[0128] The fourth selection, referred to as the fourth selection:

[0129] Add MCA-180g as an inhibitor per ton of high calcium scheelite tailings to the third concentration foam, and carry out the fourth concentration to obtain the fourth concentration foam and the fourth concentration middlings. The flotation machine used in the fourth concentration is XCF / KYF4 cubic aerated mechanical agitation flotation machine. The fourth concentration middlings are transferred to the third concentration process.

[0130] The fifth selection, referred to as Wujing:

[0131] Add MCA-160g as an inhibitor per ton of high calcium scheelite tailings to the fourth concentration foam, and carry out the fifth concentration to obtain the fifth concentration foam and the fifth concentration middlings. The flotation machine used in the fifth concentration is XCF / KYF4 cubic aerated mechanical agitation flotation machine. The fifth concentration middlings are transferred to the fourth concentration process.

[0132] The Sixth Selection, referred to as the Sixth Selection:

[0133] The fifth selected foam is subjected to the sixth selection to obtain fluorite concentrate powder and the sixth selected middlings. The flotation machine used in the sixth selection is an XCF / KYF4 cubic aerated mechanical agitation flotation machine. The fluorite concentrate powder is an acid-grade fluorite concentrate powder containing CaCO30.4%, CaF297.9%, and SiO20.06%. The recovery rate of fluorite concentrate powder is 85.6%. The sixth selected middlings are transferred to the fifth selection process.

[0134] Comparative Example 1

[0135] Proceed according to patent application CN102658242A.

[0136] The components before and after mineral processing in the mineral processing technology of the above-mentioned embodiment and comparative example are analyzed below, and the results are shown in Table 1. The receiving standard of the fluoride salt manufacturer.

[0137] Table 1 Comparison of composition before and after beneficiation process

[0138]

[0139] It can be seen from the results in Table 1 that the process method of the above embodiment of the present invention can obtain acid-grade fluorite concentrate powder containing CaCO3≤0.8%, CaF2≥96%, and SiO2≤0.1% from high-calcium scheelite tailings with CaCO3≥16% and CaF2≤25%, and improve the fluorite recovery rate to more than 82%.

[0140] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A high calcium scheelite tailings fluorite beneficiation process, characterized in that: The following steps are involved: After mixing high calcium scheelite tailings, water and a beneficiation agent, grinding is performed to obtain a grinding slurry; based on each ton of high calcium scheelite tailings, the beneficiation agent includes 100 g / t to 120 g / t of oleic acid, 280 g / t to 300 g / t of water glass, 300 g / t to 320 g / t of sulfuric acid and 60 g / t to 80 g / t of an inhibitor; After the grinding slurry is mixed with the roughing agent, roughing is performed to obtain a roughing concentrate and a roughing tailing; based on each ton of high-calcium scheelite tailings, the roughing agent includes 150 g / t to 250 g / t of oleic acid and 5 g / t to 15 g / t of water glass; The rough concentrate is subjected to multiple concentration in the presence of a concentration agent to obtain fluorite concentrate powder; the concentration agent includes an inhibitor, and the amount of the inhibitor added in each concentration is 60g / t to 100g / t per ton of high-calcium scheelite tailings; The inhibitor is obtained by mixing the following raw materials in parts by weight: 4-5 parts of sodium hexametaphosphate, 10-12 parts of sodium humate, 20-25 parts of modified starch, 30-35 parts of synthetic tannin S-804 or natural tannin, 15-20 parts of calcium lignin sulfonate and 4-5 parts of sodium sulfite.

2. The high calcium scheelite tailings fluorite beneficiation process according to claim 1 is characterized in that: High calcium scheelite tailings are high calcium scheelite tailings with CaF2≤25% and CaCO3≥16%.

3. The high calcium scheelite tailings fluorite beneficiation process according to claim 1 is characterized in that: The grinding process includes one-stage grinding process and two-stage grinding process; The first stage grinding process is to mix the high calcium scheelite tailings with water, add beneficiation reagents, and adjust the pH to 6-7, and then grind the high calcium scheelite tailings to -0.074mm ore particles accounting for 60%-65% of the total mass of the high calcium scheelite tailings; then form a closed circuit grinding with the spiral classifier, and the overflow enters the second stage grinding process; The two-stage grinding process is to use a vertical mechanical slurry pump and a hydrocyclone in parallel to form a two-stage closed-circuit grinding operation; until the high-calcium scheelite tailings are ground to -0.074mm ore particles accounting for 82% to 85% of the total mass of the high-calcium scheelite tailings, and a two-stage slurry is obtained.

4. The high calcium scheelite tailings fluorite beneficiation process according to claim 3 is characterized in that: The first-stage grinding process uses steel segments of ∮45mm×50mm as the grinding medium, or a mixture of steel segments of ∮45mm×50mm and steel segments of ∮25mm×30mm as the grinding medium; the second-stage grinding process uses steel segments of ∮25mm×30mm as the grinding medium.

5. The high calcium scheelite tailings fluorite beneficiation process according to claim 3 is characterized in that: The overflow slurry concentration of the first-stage grinding process is 30% to 35%; the overflow slurry concentration of the second-stage grinding process is 25% to 30%.

6. The high calcium scheelite tailings fluorite beneficiation process according to claim 1 is characterized in that: The beneficiation process is to beneficiate the rough concentrate 6 to 7 times, and beneficiation reagents are added in the first 5 times.

7. The high calcium scheelite tailings fluorite beneficiation process according to claim 3 is characterized in that: The selection process includes a first selection process, a second selection process, a third selection process, a fourth selection process, a fifth selection process and a sixth selection process; Calculated per ton of high-calcium scheelite tailings, the first concentrating process is to add 60g / t~100g / t of inhibitors to the rougher concentrate; the second to fifth concentrating processes are to add 60g / t~100g / t of inhibitors to the concentrating concentrate obtained in the previous concentrating process; and as the number of concentrating times increases, the amount of inhibitor added gradually decreases.

8. The high calcium scheelite tailings fluorite beneficiation process according to claim 7 is characterized in that: According to the calculation of high calcium scheelite tailings per ton, the first concentration process is to add 95g / t to 100g / t of inhibitor to the rougher concentrate, and then conduct the first concentration to obtain the first concentrated concentrate and the first concentrated middlings; Part of the first concentrated ore is transferred to the first grinding process, and part is transferred to the scavenging process; The second concentration process is to add 75g / t to 80g / t of inhibitor to the first concentration concentrate, and conduct the second concentration to obtain the second concentration concentrate and the second concentration middlings; the second concentration middlings are transferred to the first concentration process; The third concentration process is to add 75g / t to 80g / t of inhibitor to the second concentration concentrate, and perform the third concentration to obtain the third concentration concentrate and the third concentration middlings; the third concentration middlings are transferred to the second concentration process; The fourth concentration process is to add 75g / t to 80g / t of inhibitor to the third concentrated concentrate, and perform the fourth concentration to obtain the fourth concentrated concentrate and the fourth concentrated middlings; the fourth concentrated middlings are transferred to the third concentration process; The fifth concentration process is to add 60g / t to 65g / t of inhibitor to the fourth concentrated concentrate, and carry out the fifth concentration to obtain the fifth concentrated concentrate and the fifth concentrated middlings; the fifth concentrated middlings are transferred to the fourth concentration process; The sixth concentration process is to carry out the sixth concentration on the fifth concentration concentrate, and the sixth concentration is carried out to obtain fluorite concentrate powder and the sixth concentration middlings; the sixth concentration middlings are transferred to the fifth concentration process.

9. The high calcium scheelite tailings fluorite beneficiation process according to claim 8, characterized in that: After the roughing process, a scavenging process is also included, in which the roughing tailings are scavenged; the number of scavenging is 1 to 3 times; and a scavenging agent is added during the first scavenging, and the scavenging agent is oleic acid. The amount of oleic acid added is 10g / t to 20g / t per ton of high-calcium scheelite tailings.

10. The high calcium scheelite tailings fluorite beneficiation process according to claim 9, characterized in that: The scanning process includes a first scanning process, a second scanning process and a third scanning process; The first scavenging process is to mix the roughing tailings and a part of the first concentrated middlings with oleic acid and then carry out the first scavenging to obtain the first scavenging foam and the first scavenging tailings; the first scavenging foam is transferred to the roughing process; The second scavenging process is to carry out a second scavenging of the first scavenging tailings to obtain second scavenging foam and second scavenging tailings; The second scavenging foam is transferred to the first scavenging process; The third scavenging process is to carry out a third scavenging of the second scavenging tailings to obtain a third scavenging concentrate and a third scavenging tailings; the third scavenging concentrate is transferred to the second scavenging process, and the third scavenging tailings are discarded at the same time.

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