A recovery method of sulfuric acid method titanium dioxide acidolysis waste residue and application thereof

Abstract

The present application relates to the technical field of sulfuric acid method titanium dioxide tailings treatment, in particular to a recovery method of sulfuric acid method titanium dioxide acidolysis waste residue and application thereof. The recovery method of sulfuric acid method titanium dioxide acidolysis waste residue comprises the following steps: wet magnetic rough separation is performed on slurry containing sulfuric acid method titanium dioxide acidolysis waste residue to obtain wet magnetic rough separation concentrate and wet magnetic rough separation tailings; the wet magnetic rough separation tailings are subjected to gravity separation scavenging to obtain gravity separation scavenging concentrate and gravity separation scavenging tailings; the gravity separation scavenging tailings are subjected to electric separation scavenging to obtain electric separation scavenging concentrate; the electric separation scavenging concentrate is mixed with the wet magnetic rough separation concentrate and the gravity separation scavenging concentrate to obtain titanium concentrate rough ore; and the titanium concentrate rough ore is subjected to electric separation concentration to obtain titanium concentrate. The method can effectively recover titanium concentrate in sulfuric acid method titanium dioxide acidolysis waste residue, the obtained titanium concentrate has a grade of greater than 50% and a titanium yield of greater than 70%.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tailings treatment of titanium dioxide by sulfuric acid method, in particular to a recovery method of acidolysis waste residue of titanium dioxide by sulfuric acid method and application thereof. BACKGROUND

[0002] Traditional titanium dioxide production processes are mainly divided into sulfuric acid method and chlorination method. Due to the limitation of production technology and titanium ore type, most of the titanium dioxide is currently produced by the sulfuric acid method. The sulfuric acid method has lower requirements for raw materials, which leads to a large amount of acidolysis tailings in the production process. According to statistics, 0.5 tons of acidolysis tailings will be produced for every ton of titanium dioxide produced. If these acidolysis residues are disposed of, not only will it cause resource waste, but also it is not conducive to environmental protection. How to effectively treat acidolysis tailings, recover titanium resources, reduce solid waste emissions and improve resource recycling rate has important practical significance for effective use of resources and environmental protection.

[0003] The acidolysis tailings is one of the waste products produced in the production process of titanium dioxide by sulfuric acid method, which is produced by the settlement and hot filtration of acidolysis titanium liquid. In the acidolysis process, sulfuric acid cannot completely react with TiO2 in titanium concentrate to form TiOSO4 or Ti(SO4)2, and the acidolysis rate is about 96%. Therefore, part of the TiO2 not involved in the reaction is still accompanied in the acidolysis sludge, and finally discarded with the sludge, resulting in a large loss of titanium.

[0004] Regarding the resource utilization of acidolysis tailings, the early acidolysis tailings was added to cement and other building materials as solid waste. In recent years, the research reports on the titanium resource recovery technology of acidolysis tailings mainly include acid leaching method, extraction method, flotation method, magnetic separation method and gravity separation method. However, the single magnetic separation method or gravity separation method cannot completely recover the titanium in the waste residue, resulting in a low overall titanium recovery rate. At the same time, the introduction of gangue components in the separation process leads to the introduction of silicon, calcium and magnesium impurities, resulting in a low titanium grade, which can only be used as a titanium concentrate.

[0005] Therefore, the present application is proposed. SUMMARY

[0006] The first object of the present application is to provide a recovery method of acidolysis waste residue of titanium dioxide by sulfuric acid method, which can effectively recover the titanium concentrate in the acidolysis waste residue of titanium dioxide by sulfuric acid method, and the obtained titanium concentrate has a high grade.

[0007] The second object of the present application is to provide the application of the titanium concentrate obtained by the recovery method of acidolysis waste residue of titanium dioxide by sulfuric acid method in the preparation of titanium dioxide and sponge titanium, which reduces the solid waste emissions and improves the resource recycling rate.

[0008] In order to achieve the above objects of the present application, the following technical solutions are adopted:

[0009] The application provides a recovery method of sulfuric acid method titanium dioxide acidolysis waste residue, comprising the following steps:

[0010] (a) wet magnetic roughing of slurry containing sulfuric acid method titanium dioxide acidolysis waste residue is carried out to obtain wet magnetic roughing concentrate and wet magnetic roughing tailings;

[0011] (b) the wet magnetic roughing tailings are subjected to gravity separation scavenging to obtain gravity separation scavenging concentrate and gravity separation scavenging tailings;

[0012] (c) the gravity separation scavenging tailings are subjected to electric separation scavenging to obtain electric separation scavenging concentrate; the electric separation scavenging concentrate is mixed with the wet magnetic roughing concentrate of step (a) and the gravity separation scavenging concentrate of step (b) to obtain titanium concentrate rough ore;

[0013] (d) the titanium concentrate rough ore is subjected to electric separation concentration to obtain titanium concentrate.

[0014] The application also provides application of the titanium concentrate obtained by the recovery method of sulfuric acid method titanium dioxide acidolysis waste residue in preparation of titanium dioxide and titanium sponge.

[0015] Compared with the prior art, the application has the following beneficial effects:

[0016] (1) The recovery method of sulfuric acid method titanium dioxide acidolysis waste residue provided by the application can obtain high-grade titanium concentrate, which reduces solid waste discharge, improves resource recycling rate, and reduces production cost.

[0017] (2) The recovery method of sulfuric acid method titanium dioxide acidolysis waste residue provided by the application has simple process and mild conditions, and is easy to realize batch production.

[0018] (3) The recovery method of sulfuric acid method titanium dioxide acidolysis waste residue provided by the application further improves titanium grade and titanium yield by using specific magnetic field strength, stroke, stroke frequency, preheating temperature, voltage and other parameters. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the specific embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.

[0020] Figure 1 The process flow chart of the recovery method of sulfuric acid method titanium dioxide acidolysis waste residue provided by the application. EMBODIMENT

[0021] The technical solutions of the present application will be described clearly and completely below in combination with the drawings and specific embodiments, but those skilled in the art will understand that the following described embodiments are part of the embodiments of the present application, not all the embodiments, and are only used to illustrate the present application, and should not be regarded as limiting the scope of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application. The specific conditions are not specified in the embodiments, which are carried out according to the conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments used are not specified by the manufacturer, which are conventional products that can be purchased on the market.

[0022] In a first aspect, the present application provides a recovery method of acidolysis waste residue of sulfuric acid method titanium dioxide, specifically a method for recovering titanium concentrate by using acidolysis waste residue of sulfuric acid method titanium dioxide, as shown in Figure 1 The process flow diagram of the recovery method of acidolysis waste residue of sulfuric acid method titanium dioxide is shown, which specifically comprises the following steps:

[0023] (a) Wet magnetic roughing of the slurry containing acidolysis waste residue of sulfuric acid method titanium dioxide is carried out to obtain wet magnetic roughing concentrate and wet magnetic roughing tailings.

[0024] (b) The wet magnetic roughing tailings obtained in step (a) are subjected to gravity separation scavenging to obtain gravity separation scavenging concentrate and gravity separation scavenging tailings.

[0025] (c) The gravity separation scavenging tailings obtained in step (b) are subjected to electric separation scavenging to obtain electric separation scavenging concentrate.

[0026] Then the electric separation scavenging concentrate is mixed with the wet magnetic roughing concentrate obtained in step (a) and the gravity separation scavenging concentrate in step (b) to obtain titanium concentrate rough ore.

[0027] (d) The titanium concentrate rough ore obtained in step (c) is subjected to electric separation concentration to obtain titanium concentrate.

[0028] The present application processes acidolysis waste residue of sulfuric acid method titanium dioxide, which refers to the acidolysis tailings generated in the process of producing titanium dioxide by sulfuric acid method, which is generated by the settlement and hot filtration of acidolysis titanium liquid, and contains TiO2 which has not reacted with sulfuric acid.

[0029] The recovery method of acidolysis waste residue of sulfuric acid method titanium dioxide provided by the present application recovers titanium resources by means of wet magnetic roughing, gravity separation scavenging, electric separation scavenging, electric separation concentration, etc., and can obtain high-grade titanium concentrate, reduces solid waste discharge, and improves the resource recycling rate.

[0030] Specifically, the application can efficiently enrich the titanium dioxide in the sulfuric acid method titanium dioxide acidolysis waste residue through magnetic separation, gravity separation and electric separation, and obtain high-grade titanium concentrate; meanwhile, according to the differences in magnetism, specific gravity and conductivity of the gangue impurities and ilmenite in the sulfuric acid method titanium dioxide acidolysis waste residue, the application can obtain higher titanium yield through step-by-step separation of magnetic separation, gravity separation and electric separation, fully extract the titanium dioxide in the waste residue, and greatly meet the principles of waste reduction and harmless treatment.

[0031] The titanium element in the sulfuric acid method titanium dioxide acidolysis waste residue is composed of two parts of unreacted ilmenite phase and difficult-to-acidolysis rutile phase, and the impurity phase is mainly composed of silica impurities and other calcium, magnesium and aluminum impurities which do not participate in the acidolysis reaction; in addition, due to the acidolysis reaction in the production process of the sulfuric acid method titanium dioxide, there are fine particles in the acidolysis tailings, so the application can effectively avoid dust raising and ensure good separation effect through wet magnetic separation.

[0032] However, the ilmenite cannot be completely recovered through one-time magnetic separation, and the difficult-to-acidolysis rutile is not recovered; the application adopts gravity separation, separates the small part of ilmenite which is not recovered through magnetic separation and the non-magnetic rutile and impurities in the tailings of the magnetic separation rough separation according to the principle that the ilmenite and the rutile have large specific gravity, and obtains gravity separation scavenging concentrate mainly composed of ilmenite and rutile.

[0033] The rutile is also difficult to be completely enriched into the concentrate through one-time gravity separation, according to the principle that the rutile has conductivity and the silica and other impurities do not have conductivity, the application further separates the rutile in the tailings of the gravity separation scavenging according to the principle that the rutile has conductivity and the silica and other impurities do not have conductivity, and obtains electric separation scavenging concentrate mainly composed of rutile.

[0034] The titanium concentrate coarse ore obtained by combining the magnetic separation rough separation concentrate, the gravity separation scavenging concentrate and the electric separation scavenging concentrate inevitably introduces impurities in the enrichment process, according to the principle that the ilmenite and the rutile have conductivity and the silica and other impurities do not have conductivity, the impurities can be removed through electric separation at the same time of improving the titanium grade, improving the added value, and improving the downstream application range.

[0035] In some specific embodiments, the titanium concentrate obtained by the application has a titanium grade of greater than 50% and a titanium yield of greater than 70%.

[0036] In addition, the recovery method of the sulfuric acid method titanium dioxide acidolysis waste residue provided by the application has simple process and mild conditions, and is easy to realize batch production.

[0037] In some embodiments, the solid content of the slurry containing the acidolysis waste residue of the sulfuric acid process titanium dioxide is 20% to 35%, including but not limited to any one of 20%, 23%, 25%, 28%, 30%, 32%, 35%, or a range between any two of them.

[0038] In some embodiments, the magnetic field strength of the wet magnetic roughing in step (a) is 4000GS to 8000GS, including but not limited to any one of 4000GS, 5000GS, 6000GS, 7000GS, 8000GS, or a range between any two of them.

[0039] The present application can effectively separate ilmenite mineral phase from other components in the tailings by using wet magnetic separation with moderate magnetic field strength, and obtain a roughing concentrate mainly composed of ilmenite.

[0040] In some embodiments, the stroke of the gravity separation scavenging in step (b) is 15mm to 30mm, including but not limited to any one of 15mm, 18mm, 20mm, 23mm, 25mm, 28mm, 30mm, or a range between any two of them.

[0041] In some embodiments, the stroke of the gravity separation scavenging in step (b) is 200 times / min to 300 times / min, including but not limited to any one of 200 times / min, 220 times / min, 240 times / min, 250 times / min, 270 times / min, 290 times / min, 300 times / min, or a range between any two of them.

[0042] Using the above gravity separation scavenging parameters, the separation of ilmenite and rutile from impurities is facilitated.

[0043] In some embodiments, the equipment used for the gravity separation scavenging in step (c) includes a shaking table.

[0044] In some embodiments, the tailings of the gravity separation scavenging in step (c) are dried and first preheated before the electroseparation scavenging.

[0045] In some embodiments, the first preheating temperature is 120℃ to 150℃, including but not limited to any one of 120℃, 125℃, 130℃, 135℃, 140℃, 145℃, 150℃, or a range between any two of them.

[0046] In some embodiments, the voltage of the electric separation in step (c) is 14000V-18000V, including but not limited to any one of 14000V, 15000V, 16000V, 17000V, 18000V, or a range between any two of them.

[0047] The first preheating temperature and the electric separation voltage described above are conducive to further separating rutile and improving the titanium yield.

[0048] In some embodiments, the electric separation in step (c) produces an electric separation concentrate and an electric separation tailing, and the electric separation tailing is waste.

[0049] The titanium dioxide in the electric separation tailing obtained by magnetic separation, gravity separation and electric separation is difficult to recover and is discarded together with other impurities.

[0050] In some embodiments, the titanium concentrate coarse ore in step (d) is dried and second preheated.

[0051] In some embodiments, the second preheating temperature is 120-150℃, including but not limited to any one of 120℃, 125℃, 130℃, 135℃, 140℃, 145℃, 150℃, or a range between any two of them.

[0052] In some embodiments, the wet magnetic roughing concentrate obtained in step (a) and the gravity separation tailing obtained in step (b) are mixed, pressure filtered and dried before being mixed with the electric separation concentrate in step (c).

[0053] In some embodiments, the voltage of the electric separation in step (d) is 18000V-22000V, including but not limited to any one of 18000V, 19000V, 20000V, 21000V, 22000V, or a range between any two of them.

[0054] The second preheating temperature and the electric separation voltage described above are conducive to further removing impurities and improving the titanium grade.

[0055] In some embodiments, the electric separation in step (d) produces an electric separation concentrate and an electric separation tailing, and the electric separation concentrate is the titanium concentrate. The electric separation tailing can be collected and mixed with the gravity separation tailing in the next process for electric separation.

[0056] Due to the reason that the acidolysis tailings is relatively fine, part of ilmenite and rutile in the electric separation and concentration process enters the electric separation and concentration tailings, and due to the low impurity content in the titanium concentrate, the electric separation and concentration tailings has a high titanium grade, so it can be returned and mixed with the heavy separation and concentration tailings to be separated again, which can further improve the overall titanium dioxide recovery rate.

[0057] In some specific embodiments, the mass fraction of TiO2 in the titanium concentrate (i.e., the grade of the titanium concentrate) in step (d) is > 50%, including but not limited to any one of 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 60%, 62%, 65%, 67%, 70%, or a range value between any two of them.

[0058] In some specific embodiments, the overall titanium recovery rate is > 70% when the titanium concentrate is recovered by the recovery method of the acidolysis waste residue of the sulfuric acid method titanium dioxide, including but not limited to any one of 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 82%, 85%, or a range value between any two of them.

[0059] The overall titanium recovery rate refers to the mass percentage of titanium dioxide in the recovered titanium concentrate to the mass of titanium dioxide in the acidolysis waste residue of the sulfuric acid method titanium dioxide.

[0060] In a second aspect, the present application also provides the application of the titanium concentrate obtained by the recovery method of the acidolysis waste residue of the sulfuric acid method titanium dioxide in the preparation of titanium dioxide and sponge titanium.

[0061] The present application enriches the acidolysis tailings of the titanium sulfate white into high-grade titanium concentrate, which can be directly used for the production of titanium dioxide and sponge titanium, and the downstream waste residue of titanium dioxide is comprehensively recovered as upstream raw material, which is of great significance for the replenishment of raw material of titanium dioxide and reduces the cost.

[0062] The embodiments of the present application will be described in detail below with reference to the examples, but those skilled in the art will understand that the following examples are only used to illustrate the present application and should not be regarded as limiting the scope of the present application. If the specific conditions are not specified in the examples, the conventional conditions or the conditions recommended by the manufacturer are used. If the reagents or instruments used are not specified by the manufacturer, they are all conventional products that can be obtained by purchase.

[0063] The mass fraction of titanium dioxide in the acidolysis waste residue of the sulfuric acid method titanium dioxide treated in each of the following examples of the present application is 26.52 wt.% (the same batch of tailings).

[0064] Example 1

[0065] The recovery method of the acidolysis waste residue of the sulfuric acid method titanium dioxide provided in this example includes the following steps:

[0066] (1) The sulfuric acid method titanium dioxide acidolysis waste residue is mixed with water to make pulp, and a slurry with a solid content of 25% is obtained. The slurry is subjected to wet magnetic roughing by a wet magnetic separator at a magnetic field strength of 6000 GS to obtain wet magnetic roughing concentrate and wet magnetic roughing tailings.

[0067] (2) The wet magnetic roughing tailings obtained in step (1) are subjected to gravity separation by a shaking table, with a stroke of 20 mm and a stroke frequency of 250 times / min, to obtain gravity separation cleaning concentrate and gravity separation tailings.

[0068] (3) The gravity separation tailings obtained in step (2) are subjected to pressure filtration and drying, the dried gravity separation tailings are preheated to 150°C (i.e. first preheating), and then subjected to electric separation cleaning, with a voltage of 16000V, to obtain electric separation cleaning concentrate.

[0069] The wet magnetic roughing concentrate obtained in step (1) and the gravity separation cleaning concentrate obtained in step (2) are mixed and subjected to pressure filtration and drying, and then mixed with the above-mentioned electric separation cleaning concentrate to obtain titanium concentrate rough ore.

[0070] (4) The titanium concentrate rough ore obtained in step (3) is preheated to 150°C (i.e. second preheating) and then subjected to electric separation cleaning, with a voltage of 20000V, to obtain titanium concentrate.

[0071] Example 2

[0072] The recovery method of sulfuric acid method titanium dioxide acidolysis waste residue provided in this embodiment includes the following steps:

[0073] (1) The sulfuric acid method titanium dioxide acidolysis waste residue is mixed with water to make pulp, and a slurry with a solid content of 30% is obtained. The slurry is subjected to wet magnetic roughing by a wet magnetic separator at a magnetic field strength of 7000 GS to obtain wet magnetic roughing concentrate and wet magnetic roughing tailings.

[0074] (2) The wet magnetic roughing tailings obtained in step (1) are subjected to gravity separation by a shaking table, with a stroke of 30 mm and a stroke frequency of 280 times / min, to obtain gravity separation cleaning concentrate and gravity separation tailings.

[0075] (3) The gravity separation tailings obtained in step (2) are subjected to pressure filtration and drying, the dried gravity separation tailings are preheated to 140°C (i.e. first preheating), and then subjected to electric separation cleaning, with a voltage of 18000V, to obtain electric separation cleaning concentrate.

[0076] The wet magnetic roughing concentrate obtained in step (1) and the gravity separation cleaning concentrate obtained in step (2) are mixed and subjected to pressure filtration and drying, and then mixed with the above-mentioned electric separation cleaning concentrate to obtain titanium concentrate rough ore.

[0077] (4) The titanium concentrate rough ore obtained in step (3) is preheated to 140°C (i.e. second preheating), and then electroseparation is performed to obtain the titanium concentrate, wherein the voltage is 18000V.

[0078] Example 3

[0079] The recovery method of the spent acidolysis residue of the titanium dioxide by sulfuric acid method provided in the embodiment comprises the following steps:

[0080] (1) The spent acidolysis residue of the titanium dioxide by sulfuric acid method is mixed with water to obtain a slurry with a solid content of 28%. The slurry is subjected to wet magnetic rough separation by a wet magnetic separator at a magnetic field strength of 8000GS to obtain wet magnetic rough separation concentrate and wet magnetic rough separation tailings.

[0081] (2) The wet magnetic rough separation tailings obtained in step (1) are subjected to gravity separation by a shaking table at a stroke of 25mm and a stroke frequency of 260 times / min to obtain gravity separation concentrate and gravity separation tailings.

[0082] (3) The gravity separation tailings obtained in step (2) are subjected to pressure filtration and drying, and the dried gravity separation tailings are preheated to 130°C (i.e. first preheating), and then electroseparation is performed to obtain electroseparation concentrate, wherein the voltage is 17000V.

[0083] The wet magnetic rough separation concentrate obtained in step (1) and the gravity separation concentrate obtained in step (2) are mixed, and then subjected to pressure filtration and drying, and then mixed with the above-mentioned electroseparation concentrate to obtain titanium concentrate rough ore.

[0084] (4) The titanium concentrate rough ore obtained in step (3) is preheated to 130°C (i.e. second preheating), and then electroseparation is performed to obtain the titanium concentrate, wherein the voltage is 19000V.

[0085] Example 4

[0086] The recovery method of the spent acidolysis residue of the titanium dioxide by sulfuric acid method provided in the embodiment comprises the following steps:

[0087] (1) The spent acidolysis residue of the titanium dioxide by sulfuric acid method is mixed with water to obtain a slurry with a solid content of 25%. The slurry is subjected to wet magnetic rough separation by a wet magnetic separator at a magnetic field strength of 5000GS to obtain wet magnetic rough separation concentrate and wet magnetic rough separation tailings.

[0088] (2) The wet magnetic rough separation tailings obtained in step (1) are subjected to gravity separation by a shaking table at a stroke of 18mm and a stroke frequency of 200 times / min to obtain gravity separation concentrate and gravity separation tailings.

[0089] (3) The heavy selection tailings obtained in step (2) are subjected to pressure filtration and drying, and the dried heavy selection tailings are preheated to 120°C (i.e., first preheating), and then subjected to electric selection sweep selection, wherein the voltage is 16000V, to obtain electric selection sweep concentrate.

[0090] The wet magnetic roughing concentrate obtained in step (1) and the heavy selection sweep concentrate obtained in step (2) are mixed and subjected to pressure filtration and drying, and then mixed with the above-mentioned electric selection sweep concentrate to obtain titanium concentrate rough concentrate.

[0091] (4) The titanium concentrate rough concentrate obtained in step (3) is preheated to 120°C (i.e., second preheating), and then subjected to electric selection cleaning, wherein the voltage is 21000V, to obtain titanium concentrate.

[0092] Example 5

[0093] The recovery method of the acidolysis waste residue of the sulfuric acid method titanium dioxide provided in the embodiment comprises the following steps:

[0094] (1) The acidolysis waste residue of the sulfuric acid method titanium dioxide is mixed with water to obtain a slurry with a solid content of 20%. The slurry is subjected to wet magnetic roughing by a wet magnetic separator at a magnetic field strength of 4000GS to obtain wet magnetic roughing concentrate and wet magnetic roughing tailings.

[0095] (2) The wet magnetic roughing tailings obtained in step (1) are subjected to heavy selection sweep selection by a shaking table at a stroke of 15mm and a stroke frequency of 300 times / min to obtain heavy selection sweep concentrate and heavy selection sweep tailings.

[0096] (3) The heavy selection sweep tailings obtained in step (2) are subjected to pressure filtration and drying, and the dried heavy selection sweep tailings are preheated to 130°C (i.e., first preheating), and then subjected to electric selection sweep selection, wherein the voltage is 14000V, to obtain electric selection sweep concentrate.

[0097] The wet magnetic roughing concentrate obtained in step (1) and the heavy selection sweep concentrate obtained in step (2) are mixed and subjected to pressure filtration and drying, and then mixed with the above-mentioned electric selection sweep concentrate to obtain titanium concentrate rough concentrate.

[0098] (4) The titanium concentrate rough concentrate obtained in step (3) is preheated to 130°C (i.e., second preheating), and then subjected to electric selection cleaning, wherein the voltage is 22000V, to obtain titanium concentrate.

[0099] Example 6

[0100] The recovery method of the acidolysis waste residue of the sulfuric acid method titanium dioxide provided in the embodiment is basically the same as that of Example 5, except that in step (1), the solid content of the slurry is replaced by 45%, and the magnetic field strength of the wet magnetic roughing is replaced by 12000GS.

[0101] Example 7

[0102] The recovery method of the acidolysis waste residue of the titanium dioxide by sulfuric acid method provided in the embodiment is basically the same as that in embodiment 5, except that in step (2), the stroke of the heavy selection and sweeping selection is replaced by 5 mm, and the stroke frequency is replaced by 100 times / min.

[0103] Embodiment 8

[0104] The recovery method of the acidolysis waste residue of the titanium dioxide by sulfuric acid method provided in the embodiment is basically the same as that in embodiment 5, except that in step (4), the voltage of the electric selection and fine selection is replaced by 10000 V.

[0105] Comparative Example 1

[0106] The recovery method of the acidolysis waste residue of the titanium dioxide by sulfuric acid method provided in the comparative example is basically the same as that in embodiment 5, except that in step (1), dry magnetic roughing is used, and the specific method is as follows: the acidolysis waste residue of the titanium dioxide by sulfuric acid method is subjected to dry magnetic separation by a permanent magnet dry magnetic separator at a magnetic field strength of 6000 GS to obtain dry magnetic roughing concentrate and dry magnetic roughing tailings.

[0107] The wet magnetic roughing tailings in step (2) of embodiment 5 are replaced by the dry magnetic roughing tailings obtained in the above comparative example, and the wet magnetic roughing concentrate in step (3) of embodiment 5 is replaced by the dry magnetic roughing concentrate obtained in the above comparative example.

[0108] Comparative Example 2

[0109] The recovery method of the acidolysis waste residue of the titanium dioxide by sulfuric acid method provided in the comparative example is basically the same as that in embodiment 5, except that in step (2), the wet magnetic roughing tailings are directly subjected to electric selection and sweeping selection instead of heavy selection and sweeping selection.

[0110] Comparative Example 3

[0111] The recovery method of the acidolysis waste residue of the titanium dioxide by sulfuric acid method provided in the comparative example is basically the same as that in embodiment 5, except that in step (3), the wet magnetic roughing concentrate and the heavy selection and sweeping selection concentrate are directly mixed with the heavy selection and sweeping selection tailings to obtain the titanium concentrate rough concentrate instead of electric selection and sweeping selection.

[0112] Comparative Example 4

[0113] The recovery method of the acidolysis waste residue of the titanium dioxide by sulfuric acid method provided in the comparative example is basically the same as that in embodiment 5, except that in step (3), electric selection and fine selection is not performed.

[0114] Experimental Example

[0115] The grade and overall titanium yield of the titanium concentrate obtained in each embodiment and each comparative example are detected, and the results are shown in Table 1.

[0116] The grade of the titanium concentrate refers to the mass fraction of titanium dioxide in the titanium concentrate.

[0117] The overall titanium yield refers to the percentage of the mass of titanium dioxide in the recovered titanium concentrate to the mass of titanium dioxide in the acidolysis waste residue of the sulfuric acid process titanium dioxide.

[0118] Table 1: Grade and overall titanium yield of each titanium concentrate

[0119]

[0120]

[0121] Referring to Table 1, by comparing the titanium grade and titanium yield of Example 5 and Examples 6-8, it can be seen that each parameter in the recovery process has a certain influence on the titanium grade or titanium yield.

[0122] The titanium grade and titanium yield of Example 5 are slightly higher than those of Examples 6-8, which shows that the parameters such as magnetic field strength, stroke, and stroke frequency provided by the present application can further improve the titanium grade and titanium yield.

[0123] By comparing the data of Example 5 and Comparative Examples 1-4, it can be seen that each step has a significant influence on the titanium grade and titanium yield. This shows that the recovery method of the acidolysis waste residue of the sulfuric acid process titanium dioxide provided by the present application can obtain a high-grade titanium concentrate with a high titanium yield.

[0124] Therefore, the recovery method of the acidolysis waste residue of the sulfuric acid process titanium dioxide provided by the present application can obtain a high-grade titanium concentrate, which can be directly used for the production of titanium dioxide and sponge titanium, thereby reducing solid waste emissions, improving resource utilization, and reducing the production cost of titanium dioxide and sponge titanium.

[0125] Although the present application has been illustrated and described with specific embodiments, it should be understood that the above embodiments are only used to illustrate the technical solutions of the present application, and are not limiting thereof; it should be understood by those skilled in the art that the technical solutions recorded in the above embodiments can be modified, or some or all of the technical features can be replaced equivalently without departing from the spirit and scope of the present application; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application; therefore, this means that all these replacements and modifications within the scope of the present application are included in the appended claims.

Claims

1. A method for recovering sulfuric acid method titanium dioxide acidolysis waste residue, characterized in that, The method comprises the following steps: (a) wet magnetic rough separation of a slurry containing sulfuric acid method titanium dioxide acidolysis waste residue to obtain wet magnetic rough separation concentrate and wet magnetic rough separation tailings; (b) gravity separation of the wet magnetic rough separation tailings to obtain gravity separation concentrate and gravity separation tailings; (c) electric separation of the gravity separation tailings to obtain electric separation concentrate; the electric separation concentrate, the wet magnetic rough separation concentrate of step (a) and the gravity separation concentrate of step (b) are mixed to obtain titanium concentrate rough concentrate; in step (c), the gravity separation tailings are dried and first preheated before the electric separation, the first preheating temperature is 120-150 DEG C; in step (c), the electric separation voltage is 14000-18000 V; (d) electric separation of the titanium concentrate rough concentrate to obtain titanium concentrate; in step (d), the titanium concentrate rough concentrate is dried and second preheated, the second preheating temperature is 120-150 DEG C; in step (d), the electric separation voltage is 18000-22000 V; in step (d), the mass fraction of TiO2 in the titanium concentrate is > 50%; The titanium concentrate is recovered by the method, and the overall titanium recovery rate is > 70%.

2. The recovery method of the spent acidolysis sludge of titanium dioxide by the sulfuric acid method according to claim 1, characterized by, in step (a), the solid content of the slurry containing sulfuric acid method titanium dioxide acidolysis waste residue is 20-35%.

3. The recovery method of the spent acidolysis sludge of titanium dioxide by the sulfuric acid method according to claim 1, characterized by, in step (a), the magnetic field strength of the wet magnetic rough separation is 4000-8000 GS.

4. The recovery method of the spent acidolysis sludge of titanium dioxide by the sulfuric acid method according to claim 1, characterized by, in step (b), the stroke of the gravity separation is 15-30 mm, and the stroke frequency is 200-300 times / min.

5. Application of the titanium concentrate obtained by the method of claim 1-4 in the preparation of titanium dioxide and titanium sponge.

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