Tailing-free phosphate ore pretreatment process

Abstract

The invention discloses a zero-tailing phosphate ore pretreatment process which comprises the following steps: identifying basic properties of phosphate ore, sorting phosphate ore including phosphate tailings and phosphate concentrate, and preparing a sintered wall material from the phosphate tailings; the phosphate ore is sedimentary mudstone. Based on performance identification of the phosphate ore, the phosphate ore is pretreated to sort out the phosphate tailings and the phosphate concentrate, the special rapid desliming device and the flotation reagent are designed for the phosphate ore, the sorting effect is guaranteed, the phosphate tailings are used for sintering the wall material, the phosphate ore pretreatment process and the building material production process are effectively considered, and the production efficiency is improved. The method realizes enrichment of phosphate concentrate and utilization of phosphate tailings, further realizes zero tailings, simple process, low consumption and environmental protection, eliminates potential threats to the environment and human health caused by a large amount of heavy metal elements and chemical substances contained in the phosphate tailings, and is suitable for the field of phosphate ores, especially collophanite.

Description

Technical Field

[0001] The invention belongs to the technical field of ore utilization, and in particular relates to a zero-tailings phosphate ore pretreatment process. Background Art

[0002] Usually, tailings are generated during the processing of ore. According to the source, tailings can be roughly divided into two types: (1) by-products of ore mining, which are similar in composition to natural sand and gravel and can be used for mine backfill or sold directly as natural aggregate; (2) the part of the product of the sorting operation during ore dressing that has a low content of the target component and cannot be used for production. Sorting operation is a pretreatment method for ore, including physical ore dressing, chemical ore dressing and physical and chemical ore dressing. Physical ore dressing mainly includes gravity separation, magnetic separation and flotation. Since the ore dressing process increases the efficiency of ore dressing by adding reagents to amplify the difference in specific gravity or magnetic properties of the materials, the tailings produced by this method are often rich in these reagents and difficult to use. Chemical ore dressing mainly includes acid leaching, alkali leaching and solvent extraction. The tailings produced by this method often need to be neutralized before discharge. The neutralization process often introduces other elements. For example, the tailings produced by the acid leaching process often add a large amount of lime to neutralize, resulting in too high a calcium content in the tailings, making subsequent treatment difficult and cumbersome. Physical and chemical beneficiation combines physical beneficiation with chemical beneficiation, and is more likely to have the disadvantages of both methods. Therefore, the utilization and post-processing of tailings have always been a pain point for resource-based industries, and how to achieve zero tailings technology has become a technical problem that needs to be solved urgently in the industry.

[0003] Collophanite is a phosphate mineral, a common name for low-grade sedimentary phosphorite, which is often cemented together with dolomite carbonates and fine particles such as silicon materials and mud minerals. Since collophanite is mostly characterized by "poor and fine impurities" and has a high silicon and magnesium content, it is difficult to separate. At present, most of the mineral processing methods used are flotation or flotation combined with other processes, including scrubbing and desludging, flotation, roasting-digestion, heavy medium beneficiation, photoelectric beneficiation and biological beneficiation. However, due to the inaccurate judgment of the type and composition of mud materials in phosphate ore and the lack of pertinence, it is still difficult to achieve a zero tailings process through appropriate phosphate ore pretreatment.

[0004] Research has found that the solid waste collophanite tailings generated during the beneficiation and enrichment of collophanite contain a large amount of heavy metal elements and chemicals, such as chromium, nickel, lead, mercury, fluoride, etc. If these substances are not properly treated and disposed of, they will pose a potential threat to the environment and human health. For example, fluoride pollutes land and water sources, participates in the formation of acid rain to destroy the natural environment, or enters the human body through air, soil, drinking water, etc., causing rickets and fluoride poisoning. Therefore, it is of great significance to achieve zero tailings process through phosphate rock pretreatment.

[0005] At the same time, the current utilization of phosphate tailings includes filling mine goafs, extracting valuable elements, and producing building materials. Among them, the production of building materials has the highest cost-effectiveness and the best application prospects. However, the phosphate ore pretreatment process often gives priority to the sorting efficiency of the target mineral without considering the characteristics of the building materials production process, resulting in a disconnect between the two and making it difficult to achieve a balance between phosphate ore pretreatment and subsequent utilization. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a zero-tailing phosphate ore pretreatment process in view of the deficiencies of the above-mentioned prior art. The method is based on the performance identification of phosphate ore, pre-treats the phosphate ore to separate phosphate tailings and phosphate concentrate, and uses the phosphate tailings for sintering wall materials, effectively taking into account the phosphate ore pretreatment process and the building materials production process, realizing the enrichment of phosphate concentrate and the utilization of phosphate tailings, and solving the problem of disconnection between phosphate ore pretreatment and subsequent utilization.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is: a zero-tailings phosphate ore pretreatment process, characterized in that the process includes: identification of basic properties of phosphate ore, and separation of phosphate ore including phosphate tailings and phosphate concentrate; the phosphate ore is sedimentary mudstone, and the mass content of silicon dioxide in the chemical composition is not more than 20%, the main mineral components include fluoroapatite, dolomite, and quartz with a total mass proportion of not less than 60%, and the mass proportion of quartz is not more than 20%, and the auxiliary mineral components include kaolinite, illite, montmorillonite, and feldspar with a total mass proportion of not more than 30%.

[0008] The above-mentioned zero-tailings phosphate rock pretreatment process is characterized in that the identification of the basic properties of the phosphate rock includes phosphate rock mineral composition analysis, phosphate rock chemical composition analysis and phosphate rock mud composition identification.

[0009] The above-mentioned zero-tailing phosphate ore pretreatment process is characterized in that the process of identifying the composition of the phosphate ore mud is as follows: crushing the phosphate ore to 200 mesh, mixing and stirring with the desludging liquid in a mass to volume ratio of 1g:1mL, standing for 24 hours to make a mixed slurry, and then pouring the mixed slurry into a rapid desludging device equipped with a 300-mesh screen for desludging for 10 minutes, drying the mud collected in the desludging device to constant weight, and then performing component identification, and the standard for component identification is: (1) if the total mass proportion of kaolinite, illite, and montmorillonite in the mineral composition is greater than 50%, the mud material is judged to be clay mud (class I); (2) if the total mass proportion of quartz, illite, and feldspar in the mineral composition is greater than 50%, the mud material is judged to be feldspar mud (class II); (3) if the total mass proportion of apatite, dolomite, and quartz in the mineral composition is greater than 50%, the mud material is judged to be apatite mud (class III).

[0010] During the research process of the present invention, it was found that the mud material in the collophanite can be defined as the material that is most easily ground during the grinding process and has viscosity and is easily adsorbed on other mineral particles, and clay minerals, feldspar minerals, and apatite minerals all have this feature. Therefore, the present invention uses a rapid desludging device to desludify the crushed phosphate ore, and in the desludging process, according to the characteristics of the mud material type, a weak acid solution such as a citric acid solution is used as a desludging liquid, so that the mud material in the collophanite is fully dispersed in the desludging liquid, so as to facilitate the subsequent identification of the mud components of the phosphate ore; at the same time, the rapid desludging device of the present invention uses an air stone, and by connecting an air pump to inflate, the air stone generates dense tiny bubbles that hit the surface of the crushed phosphate ore particles. The force generated by the bursting of the bubbles causes the mud material to detach and disperse in the desludging liquid, thereby increasing the amount of mud material extracted, and thus improving the accuracy of the analysis and identification of the mud components of the phosphate ore. The rapid desludging device has a simple structure, is easy to use, has low cost, and has high accuracy.

[0011] The above-mentioned zero-tailings phosphate ore pretreatment process is characterized in that the rapid demudifier includes a mud cup and a material receiving screen located at the upper layer inside the mud cup through a bracket support, an air stone is placed at the bottom of the mud cup, the air stone is connected to an air pump through a hose, and a timer is connected to the air pump. The above-mentioned zero-tailing phosphate ore pretreatment process is characterized in that the phosphate tailings and phosphate concentrate in the phosphate ore are separated by flotation, and the flotation includes forward flotation and reverse flotation; When the mud material in the phosphate ore is clay mud (Class I), positive flotation is used, and the flotation reagents include, by mass percentage: 5% anhydrous calcium chloride, 85% anhydrous aluminum chloride, 5% hexahydrate ferric chloride, 5% sodium hydroxide, and the amount of flotation reagents is 5% of the mass of the phosphate ore, and the flotation products are phosphate tailings and sludge phosphate concentrate, and the phosphate tailings are Class I slag; When the mud material in the phosphate ore is feldspar mud (Class II), positive flotation is adopted, and the flotation reagents include, by mass percentage, 10% sodium carbonate, 80% anhydrous aluminum chloride, 5% magnesium chloride hexahydrate, and 5% TCP, and the dosage of the flotation reagent is 3% of the mass of the phosphate ore, and the flotation product phosphate tailings and sludge phosphate concentrate are obtained, and the phosphate tailings are Class II slag; When the mud material in the phosphate ore is apatite mud (Class III), reverse flotation is used, and the flotation reagents include, by mass, 90% anhydrous aluminum chloride, 5% TCP, and 5% sodium hydroxide, and the dosage of the flotation reagent is 3% of the mass of the phosphate ore, to obtain the flotation product phosphate concentrate and sludge phosphate tailings, and the phosphate tailings are Class III slag.

[0012] Existing phosphate rock flotation agents usually have average effects in neutral environments and better effects in weakly acidic environments. The desludging flotation effect is best when the pH is 6-6.5, and the desludging flotation effect becomes worse when the pH is less than 5. In addition, lime must be added to the tailings slurry for neutralization before it can be discharged or utilized, which is not conducive to the application of tailings in sintered wall materials.

[0013] The present invention specifically designs flotation methods and flotation agents for different types of mud materials in collophanite. The main mechanisms of flotation agents include two action mechanisms: electrostatic repulsion and steric hindrance. When a particle is charged, an equal amount of countercharge will be adsorbed around its interface to form a double electrical layer structure. The attractive force between particles is the van der Waals force, while the mutually repulsive force is generated by the charged particles. When particles approach, the ion concentration in the overlapping area increases, causing ion redistribution, generating repulsion, and separating the particles. The steric hindrance mechanism involves the adsorption of high molecular polymers on the surface of colloidal particles to prevent particles from agglomerating. This mechanism is firmly adsorbed on the surface of pigment particles through the anchoring group of the high molecular dispersant, forming an adsorption layer of a certain thickness, maintaining the distance between particles, and preventing agglomeration.

[0014] The present invention has found that the mud material in the colloidal phosphate ore has the characteristics of a high molecular polymer, and apatite is similar to a colloid. The combination process of apatite and mud material is dynamic, and the degree of combination changes with changes in external conditions such as temperature, pH, and consistency.

[0015] Among them, for the clay mud (type I) in phosphate rock, a flotation agent composed of anhydrous calcium chloride, anhydrous aluminum chloride, hexahydrate ferric chloride, and sodium hydroxide is used. Since aluminum chloride has a stronger effect on apatite, it can effectively separate the combination of apatite and mud materials. Calcium chloride has a strong adsorption effect on clay mud. The two together produce a steric hindrance effect, and the addition of hexahydrate ferric chloride changes the charge type of apatite and clay mud particles, generating electrostatic repulsion. Sodium hydroxide improves the environmental pH, thereby achieving excellent flotation effects. At the same time, the chlorine element in the flotation agent component volatilizes at 600°C, and the sodium, calcium, and iron elements combine with aluminum, silicon and other elements at 1100°C~1150°C in an alkaline environment to form new feldspar crystals as bone-forming crystals, so they are suitable for subsequent sintering wall material processes.

[0016] For the feldspar mud (category II) in phosphate ore, a flotation agent composed of sodium carbonate, anhydrous aluminum chloride, magnesium chloride hexahydrate, and TCP (tricresyl phosphate) is used. Since aluminum chloride has a stronger effect on apatite, it can effectively separate the combination of apatite and mud. Sodium carbonate has a strong adsorption effect on feldspar mud. The two together produce a steric hindrance effect. The addition of magnesium chloride hexahydrate changes the charged type of apatite and feldspar mud particles, generating electrostatic repulsion. TCP improves the environmental consistency, thereby achieving excellent flotation effect. At the same time, TCP in the flotation agent component volatilizes at 400℃ and chlorine at 600℃. Calcium and magnesium combine with aluminum, silicon and other elements at 1100℃~1150℃ in an alkaline environment to form new feldspar crystals as bone-forming crystals, so they are suitable for subsequent sintering wall material processes.

[0017] For the mud material of apatite mud (three types) in phosphate ore, a flotation agent composed of anhydrous aluminum chloride, TCP, and sodium hydroxide is used. Since aluminum chloride has a stronger effect on apatite, it can effectively split the combination of apatite and mud material, producing a steric hindrance effect, and at the same time improve the electrostatic repulsion of apatite charged species, TCP improves the environmental consistency, and sodium hydroxide improves the environmental pH, thereby achieving excellent flotation effect. At the same time, TCP in the flotation agent component volatilizes at 400℃, chlorine at 600℃, and sodium combines with aluminum, silicon and other elements at 1100℃~1150℃ in an alkaline environment to form new feldspar crystals as bone-forming crystals, so it is suitable for subsequent sintering wall material processes.

[0018] In addition, the flotation agents designed for different mud materials in phosphate ore in the present invention are best under neutral or weakly alkaline conditions, especially at pH=7.1, and can be directly used in the next process without neutralization. The process flow is simple, the product quality is high, the energy consumption is low, the environment is environmentally friendly and pollution-free, and the economic benefits are good.

[0019] The above-mentioned zero-tailings phosphate ore pretreatment process is characterized in that the sorted phosphate tailings are used to prepare sintered wall materials, wherein the sintered wall materials are solid bricks including sintered pavement bricks and sintered wall bricks, and the raw materials for preparing the sintered wall materials include 90% to 95% of the main material phosphate tailings and 5% to 10% of the auxiliary material adjustment materials by weight, wherein the mass proportion of the first type of slag in the main material phosphate tailings is 15% to 25%, the mass proportion of the second type of slag is 15% to 25%, the mass proportion of the third type of slag is 50% to 70%, and the auxiliary material adjustment materials include: 60% brick slag, 10% river sand and 30% coal powder by weight; The preparation process of the sintered wall material comprises the following steps: Step 1: Mixing the raw materials: Add water to the main material and the auxiliary material and mix them evenly to obtain a mixture; the mass of the water added is 5% of the mass of the dry materials in the main material and the auxiliary material; Step 2: Static aging: The mixture in step 1 is kept static for 24 hours at a temperature not lower than 15°C; Step 3, compression molding: statically press the mixed material after constant temperature static in step 2 to obtain a compact; the static pressing pressure is 40 tons to 50 tons per compact; Step 4, sintering: placing the compact obtained in step 3 in an electric furnace for sintering, taking it out after cooling down, and obtaining a sintered wall material; the sintering system is: at a heating rate of 3°C / min, first heating from room temperature to 200°C and keeping warm for 4 hours, then heating to 600°C and keeping warm for 1 hour, then heating to 900°C and keeping warm for 1.5 hours, and then heating to the firing temperature of 1100°C~1200°C and keeping warm for 4 hours; the cooling system is: at a cooling rate of 10°C / min, first cooling from the firing temperature to 900°C and keeping warm for 1 hour, and then cooling to room temperature. It is found through testing that the main component of the phosphate tailings of the present invention is apatite, and its main component is tricalcium phosphate skeleton-forming material. The residual tricalcium phosphate, clay, and quartz in the phosphate tailings constitute a sintering system of tricalcium phosphate-clay-quartz, which has sintering properties at 1150°C. Compared with the process of traditional sintering systems such as kaolin-quartz-feldspar system, in which kaolin is converted into metakaolin and then into mullite skeleton-forming minerals, and then the high-temperature melt formed by feldspar and quartz is filled into the gaps of the skeleton to form a solid block, the tricalcium phosphate in the tricalcium phosphate-clay-quartz system itself is a skeleton-forming material, and only needs to be filled after the quartz and clay are melted, so the sintering time of the system is greatly shortened, reducing the preparation process of sintered wall materials, and has good application prospects. Compared with the prior art, the present invention has the following advantages: 1. The present invention identifies the properties of phosphate ore, pre-treats the phosphate ore to separate phosphate tailings and phosphate concentrate, and uses the phosphate tailings for sintering wall materials, effectively taking into account the phosphate ore pretreatment process and the building materials production process, achieving the enrichment of phosphate concentrate and the utilization of phosphate tailings, and then achieving zero tailings, eliminating the potential threat to the environment and human health caused by a large amount of heavy metal elements and chemicals in the phosphate tailings.

[0020] 2. The present invention designs a special and simple-structured rapid desludging device for phosphate ore, which promotes the separation and dispersion of mud materials in the colloidal phosphate ore, increases the amount of mud materials extracted, and further improves the accuracy of analysis and identification of phosphate ore mud components, ensuring the smooth progress of the phosphate ore pretreatment process.

[0021] 3. The present invention specifically designs flotation methods and flotation agents for different types of mud materials in phosphate ore, and takes into account the subsequent sintering wall material process, so as to achieve excellent flotation effect on different types of phosphate ore, ensure the separation effect of phosphate concentrate and phosphate tailings, and then achieve zero tailings, and can enter the next procedure for utilization without neutralization, with simple process, low consumption and environmental protection.

[0022] 4. The phosphate tailings obtained by the present invention is a sintering system of tricalcium phosphate-clay-quartz, which only needs to be filled after quartz and clay are melted, which greatly shortens the sintering time of sintered wall materials and simplifies the process flow.

[0023] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the structure of the rapid desludging device in the present invention.

[0025] Description of Reference Numerals DETAILED DESCRIPTION

[0026] like Figure 1 As shown, the rapid demudifier of the present invention includes a mud cup 1 and a material receiving screen 2 located at the upper layer inside the mud cup 1 and supported by a bracket 3, an air stone 4 is placed at the bottom of the mud cup 1, and the air stone 4 is connected to an air pump 5 through a hose, and a timer 6 is connected to the air pump 5.

[0027] In the rapid demudifiers in Examples 1 to 7 of the present invention, the mud cup 1 adopts a standard 2000mL beaker with a bottom diameter of 134mm and a height of 196mm; the material receiving screen 2 is a 150-mesh standard screen with a diameter of 10cm; the height of the bracket 3 is 80mm and the material is stainless steel; the diameter of the air stone 4 is 6cm and the thickness is 1.5cm, and the aperture of the interface connected to the hose is 0.5cm; the specification of the air pump 5 is 5W, and the aperture of the interface connected to the hose is 0.5cm.

[0028] The method of using the rapid desludging device of the present invention is as follows: the air stone 4 is connected to the air pump 5 through a hose and then placed flat on the bottom of the mud cup 1, and 200 mL of water is added to soak the air stone 4, and then the bracket 3 and the material screen 2 are placed in the mud cup 1, the mixed slurry is placed on the material screen 2, and the desludging liquid, i.e., a citric acid solution with a mass concentration of 35%, is added to the 2000 mL scale, and the timing time is set using the timer 6, the air pump 5 is powered on to pump air for rapid desludging, and the material on the material screen 2 is gently stirred with a glass rod every 5 minutes, the power is turned off after the timing is completed, and the mud in the mud cup 1 is taken to identify the phosphate ore mud composition.

[0029] Example 1 The process of this embodiment includes: identification of basic properties of phosphate ore, separation of phosphate ore including phosphate tailings and phosphate concentrate; The identification of the basic properties of phosphate ore includes phosphate ore mineral composition analysis, phosphate ore chemical composition analysis and phosphate ore mud composition identification, wherein the results of phosphate ore mineral composition analysis and phosphate ore chemical composition analysis are shown in Tables 1 and 2 below, and the phosphate ore is sedimentary mudstone; Table 1 Chemical composition analysis results of phosphate rock (%)

[0030] Table 2 Analysis results of mineral composition of phosphate rock (%)

[0031] Among them, the process of identifying the composition of phosphate rock mud is as follows: crush the phosphate rock to 200 mesh, mix and stir with a citric acid solution with a mass concentration of 35% of the desludging liquid at a mass to volume ratio of 1g:1mL, let it stand for 24 hours to make a mixed slurry, and then pour the mixed slurry into a rapid desludging device equipped with a 300-mesh screen to desludging for 10 minutes, dry the mud collected in the desludging device to constant weight, and then identify the composition. The results show that the total mass proportion of kaolinite, illite, and montmorillonite in the mineral composition is greater than 50%, and the mud material is determined to be clay mud (Class I); The phosphate tailings and phosphate concentrate in the phosphate ore are separated by positive flotation. The flotation reagents include, by mass, 5% anhydrous calcium chloride, 85% anhydrous aluminum chloride, 5% ferric chloride hexahydrate, and 5% sodium hydroxide. The amount of flotation reagent is 5% of the mass of the phosphate ore. The flotation products are phosphate tailings and sludge phosphate concentrate, and the phosphate tailings are Class I slag.

[0032] Example 2 The process of this embodiment includes: identification of basic properties of phosphate ore, separation of phosphate ore including phosphate tailings and phosphate concentrate; The identification of the basic properties of phosphate ore includes phosphate ore mineral composition analysis, phosphate ore chemical composition analysis and phosphate ore mud composition identification, wherein the results of phosphate ore mineral composition analysis and phosphate ore chemical composition analysis are shown in Tables 3 and 4 below, and the phosphate ore is sedimentary mudstone; Table 3 Chemical composition analysis results of phosphate rock (%)

[0033] Table 4 Analysis results of mineral composition of phosphate rock (%)

[0034] Among them, the process of identifying the composition of phosphate rock mud is as follows: crush the phosphate rock to 200 mesh, mix and stir with a citric acid solution with a mass concentration of 35% of the desludging liquid at a mass to volume ratio of 1g:1mL, let it stand for 24 hours to make a mixed slurry, and then pour the mixed slurry into a rapid desludging device equipped with a 300-mesh screen to desludging for 10 minutes, dry the mud collected in the desludging device to constant weight, and then identify the composition. The results show that the total mass proportion of quartz, illite, and feldspar in the mineral composition is greater than 50%, and the mud material is determined to be feldspar mud (Class II); Direct flotation is used to separate the phosphate tailings and phosphate concentrate in the phosphate ore. The flotation reagents include, by mass, 10% sodium carbonate, 80% anhydrous aluminum chloride, 5% magnesium chloride hexahydrate, and 5% TCP. The dosage of the flotation reagent is 3% of the mass of the phosphate ore. The flotation products are phosphate tailings and sludge phosphate concentrate, and the phosphate tailings are Class II slag.

[0035] Example 3 The process of this embodiment includes: identification of basic properties of phosphate ore, separation of phosphate ore including phosphate tailings and phosphate concentrate; The identification of the basic properties of phosphate ore includes phosphate ore mineral composition analysis, phosphate ore chemical composition analysis and phosphate ore mud composition identification, wherein the results of phosphate ore mineral composition analysis and phosphate ore chemical composition analysis are shown in Tables 5 and 6 below, and the phosphate ore is sedimentary mudstone; Table 5 Chemical composition analysis results of phosphate rock (%)

[0036] Table 6 Analysis results of mineral composition of phosphate rock (%)

[0037] Among them, the process of identifying the composition of phosphate rock mud is as follows: crush the phosphate rock to 200 mesh, mix and stir with a citric acid solution with a mass concentration of 35% of the desludging liquid at a mass to volume ratio of 1g:1mL, let it stand for 24 hours to make a mixed slurry, and then pour the mixed slurry into a rapid desludging device equipped with a 300-mesh screen for desludging for 10 minutes, dry the mud collected in the desludging device to constant weight, and then identify the composition. The results show that the total mass proportion of apatite, dolomite, and quartz in the mineral composition is greater than 50%, and the mud material is determined to be apatite mud (Class III); Reverse flotation is used to separate the phosphate tailings and phosphate concentrate in the phosphate ore. The flotation reagents include: 90% anhydrous aluminum chloride, 5% TCP, and 5% sodium hydroxide by mass. The amount of flotation reagent is 3% of the mass of the phosphate ore. The flotation product is phosphate concentrate and sludge phosphate tailings, and the phosphate tailings are Class III slag.

[0038] Example 4 In this embodiment, the three types of phosphorus tailings prepared in Examples 1 to 3 are used to prepare sintered pavement bricks. The raw materials for preparing the sintered pavement bricks include 90% of the main phosphorus tailings and 10% of the auxiliary material adjustment materials by weight, wherein the first type of slag in the main phosphorus tailings accounts for 25% by weight, the second type of slag accounts for 25% by weight, and the third type of slag accounts for 50% by weight. The auxiliary material adjustment materials include: 60% brick slag, 10% river sand and 30% coal powder by weight; The preparation process of the sintered pavement brick comprises the following steps: Step 1: Mixing the raw materials: Add water to the main material and the auxiliary material and mix them evenly to obtain a mixture; the mass of the water added is 5% of the mass of the dry materials in the main material and the auxiliary material; Step 2: Static aging: The mixture in step 1 is kept static for 24 hours at a temperature not lower than 15°C; Step 3, compression molding: statically press the mixed material after constant temperature static in step 2 to obtain a compact; the static pressing pressure is 40 tons / piece of compact; Step 4, sintering: placing the pressed green sheet obtained in step 3 in an electric furnace for sintering, taking it out after cooling down, and obtaining sintered pavement bricks; the sintering system is: heating up from room temperature to 200°C for 4 hours at a heating rate of 3°C / min, then heating up to 600°C for 1 hour, then heating up to 900°C for 1.5 hours, and then heating up to the firing temperature of 1100°C~1200°C for 4 hours; the cooling system is: cooling down from the firing temperature to 900°C for 1 hour at a cooling rate of 10°C / min, and then cooling down to room temperature.

[0039] After testing, the sintered pavement bricks prepared in this embodiment meet various indicators of GB / T 26001-2010 "Sintered Pavement Bricks".

[0040] Example 5 In this embodiment, the three types of phosphorus tailings prepared in Examples 1 to 3 are used to prepare sintered pavement bricks. The raw materials for preparing the sintered pavement bricks include 95% of the main phosphorus tailings and 5% of the auxiliary material adjustment materials by weight, wherein the main phosphorus tailings include 15% of the first-class slag by weight, 15% of the second-class slag by weight, and 70% of the third-class slag by weight. The auxiliary material adjustment materials include: 60% brick slag, 10% river sand, and 30% coal powder by weight; The preparation process of the sintered pavement brick comprises the following steps: Step 1: Mixing the raw materials: Add water to the main material and the auxiliary material and mix them evenly to obtain a mixture; the mass of the water added is 5% of the mass of the dry materials in the main material and the auxiliary material; Step 2: Static aging: The mixture in step 1 is kept static for 24 hours at a temperature not lower than 15°C; Step 3, compression molding: statically press the mixed material after constant temperature static in step 2 to obtain a compact; the static pressing pressure is 50 tons / piece compact; Step 4, sintering: placing the pressed green sheet obtained in step 3 in an electric furnace for sintering, taking it out after cooling down, and obtaining sintered pavement bricks; the sintering system is: heating up from room temperature to 200°C for 4 hours at a heating rate of 3°C / min, then heating up to 600°C for 1 hour, then heating up to 900°C for 1.5 hours, and then heating up to the firing temperature of 1100°C~1200°C for 4 hours; the cooling system is: cooling down from the firing temperature to 900°C for 1 hour at a cooling rate of 10°C / min, and then cooling down to room temperature.

[0041] After testing, the sintered pavement bricks prepared in this embodiment meet various indicators of GB / T 26001-2010 "Sintered Pavement Bricks".

[0042] Example 6 In this embodiment, the three types of phosphorus tailings prepared in Examples 1 to 3 are used to prepare sintered wall bricks. The raw materials for preparing the sintered wall bricks include 92% of the main phosphorus tailings and 8% of the auxiliary material adjustment materials by weight, wherein the mass proportion of the first type of slag in the main phosphorus tailings is 20%, the mass proportion of the second type of slag is 15%, and the mass proportion of the third type of slag is 65%. The auxiliary material adjustment materials include: 60% brick slag, 10% river sand and 30% coal powder by weight; The preparation process of the sintered wall brick comprises the following steps: Step 1: Mixing the raw materials: Add water to the main material and the auxiliary material and mix them evenly to obtain a mixture; the mass of the water added is 5% of the mass of the dry materials in the main material and the auxiliary material; Step 2: Static aging: The mixture in step 1 is kept static for 24 hours at a temperature not lower than 15°C; Step 3, compression molding: statically press the mixed material after constant temperature static in step 2 to obtain a compact; the static pressing pressure is 40 tons / piece of compact; Step 4, sintering: placing the pressed green sheet obtained in step 3 in an electric furnace for sintering, taking it out after cooling down, and obtaining sintered wall tiles; the sintering system is: heating up from room temperature to 200°C for 4 hours at a heating rate of 3°C / min, then heating up to 600°C for 1 hour, then heating up to 900°C for 1.5 hours, and then heating up to the firing temperature of 1100°C~1200°C for 4 hours; the cooling system is: cooling down from the firing temperature to 900°C for 1 hour at a cooling rate of 10°C / min, and then cooling down to room temperature.

[0043] After testing, the sintered wall bricks prepared in this embodiment meet the various indicators of GB / T 5101-2017 "Sintered Ordinary Bricks".

[0044] Example 7 In this embodiment, the three types of phosphorus tailings prepared in Examples 1 to 3 are used to prepare sintered wall bricks. The raw materials for preparing the sintered wall bricks include 91% of the main phosphorus tailings and 9% of the auxiliary material adjustment materials by weight, wherein the mass proportion of the first type of slag in the main phosphorus tailings is 23%, the mass proportion of the second type of slag is 18%, and the mass proportion of the third type of slag is 59%. The auxiliary material adjustment materials include 60% brick slag, 10% river sand and 30% coal powder by weight; The preparation process of the sintered wall brick comprises the following steps: Step 1: Mixing the raw materials: Add water to the main material and the auxiliary material and mix them evenly to obtain a mixture; the mass of the water added is 5% of the mass of the dry materials in the main material and the auxiliary material; Step 2: Static aging: The mixture in step 1 is kept static for 24 hours at a temperature not lower than 15°C; Step 3, compression molding: statically press the mixed material after constant temperature static in step 2 to obtain a compact; the static pressing pressure is 50 tons / piece compact; Step 4, sintering: placing the pressed green sheet obtained in step 3 in an electric furnace for sintering, taking it out after cooling down, and obtaining sintered wall tiles; the sintering system is: heating up from room temperature to 200°C for 4 hours at a heating rate of 3°C / min, then heating up to 600°C for 1 hour, then heating up to 900°C for 1.5 hours, and then heating up to the firing temperature of 1100°C~1200°C for 4 hours; the cooling system is: cooling down from the firing temperature to 900°C for 1 hour at a cooling rate of 10°C / min, and then cooling down to room temperature.

[0045] After testing, the sintered wall bricks prepared in this embodiment meet the various indicators of GB / T 5101-2017 "Sintered Ordinary Bricks".

[0046] The above is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent change made to the above embodiment according to the technical essence of the invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A zero tailings phosphate ore pretreatment process, characterized in that: The process includes: identification of basic properties of phosphate ore, and separation of phosphate ore including phosphate tailings and phosphate concentrate; the phosphate ore is sedimentary mudstone, and the silicon dioxide mass content in the chemical composition is not more than 20%, the main mineral components include fluoroapatite, dolomite, and quartz with a total mass proportion of not less than 60%, and the mass proportion of quartz is not more than 20%, and the auxiliary mineral components include kaolinite, illite, montmorillonite, and feldspar with a total mass proportion of not more than 30%.

2. A zero tailings phosphate ore pretreatment process according to claim 1, characterized in that: The identification of the basic properties of phosphate rock includes phosphate rock mineral composition analysis, phosphate rock chemical composition analysis and phosphate rock mud composition identification.

3. A zero tailings phosphate ore pretreatment process according to claim 2, characterized in that: The process of identifying the composition of phosphate rock mud is as follows: crushing the phosphate rock to 200 mesh, mixing and stirring with the desludging liquid in a mass-to-volume ratio of 1 g: 1 mL, standing for 24 hours to prepare a mixed slurry, and then pouring the mixed slurry into a rapid desludging device equipped with a 300-mesh screen for desludging for 10 minutes, drying the mud collected in the desludging device to constant weight, and then performing composition identification. The standard for composition identification is: (1) if the total mass proportion of kaolinite, illite, and montmorillonite in the mineral composition is greater than 50%, the mud material is determined to be clay mud (Class I); (2) if the total mass proportion of quartz, illite, and feldspar in the mineral composition is greater than 50%, the mud material is determined to be feldspar mud (Class II); (3) if the total mass proportion of apatite, dolomite, and quartz in the mineral composition is greater than 50%, the mud material is determined to be apatite mud (Class III).

4. A zero tailings phosphate ore pretreatment process according to claim 3, characterized in that: The rapid demudifier comprises a mud cup (1) and a material receiving screen (2) located at an upper layer inside the mud cup (1) and supported by a bracket (3); an air stone (4) is placed at the bottom of the mud cup (1); the air stone (4) is connected to an air pump (5) via a hose; and the air pump (5) is connected to a timer (6).

5. A zero tailings phosphate ore pretreatment process according to claim 3, characterized in that: The phosphate tailings and phosphate concentrate in the phosphate ore are separated by flotation, wherein the flotation includes forward flotation and reverse flotation; When the mud material in the phosphate ore is clay mud (Class I), positive flotation is used, and the flotation reagents include, by mass percentage: 5% anhydrous calcium chloride, 85% anhydrous aluminum chloride, 5% hexahydrate ferric chloride, 5% sodium hydroxide, and the amount of flotation reagents is 5% of the mass of the phosphate ore, and the flotation products are phosphate tailings and sludge phosphate concentrate, and the phosphate tailings are Class I slag; When the mud material in the phosphate ore is feldspar mud (Class II), positive flotation is adopted, and the flotation reagents include, by mass percentage, 10% sodium carbonate, 80% anhydrous aluminum chloride, 5% magnesium chloride hexahydrate, and 5% TCP, and the dosage of the flotation reagent is 3% of the mass of the phosphate ore, and the flotation product phosphate tailings and sludge phosphate concentrate are obtained, and the phosphate tailings are Class II slag; When the mud material in the phosphate ore is apatite mud (Class III), reverse flotation is used, and the flotation reagents include, by mass, 90% anhydrous aluminum chloride, 5% TCP, and 5% sodium hydroxide, and the dosage of the flotation reagent is 3% of the mass of the phosphate ore, to obtain the flotation product phosphate concentrate and sludge phosphate tailings, and the phosphate tailings are Class III slag.

6. A zero tailings phosphate ore pretreatment process according to claim 5, characterized in that: The sorted phosphorus tailings are used to prepare sintered wall materials, wherein the sintered wall materials are solid bricks including sintered pavement bricks and sintered wall bricks, and the raw materials for preparing the sintered wall materials include 90% to 95% of the main phosphorus tailings and 5% to 10% of the auxiliary materials by weight, wherein the first-class slag accounts for 15% to 25% of the main phosphorus tailings, the second-class slag accounts for 15% to 25% of the main phosphorus tailings, the third-class slag accounts for 50% to 70% of the main phosphorus tailings, and the auxiliary materials by weight include: 60% brick slag, 10% river sand and 30% coal powder; The preparation process of the sintered wall material comprises the following steps: Step 1: Mixing the raw materials: Add water to the main material and the auxiliary material and mix them evenly to obtain a mixture; the mass of the water added is 5% of the mass of the dry materials in the main material and the auxiliary material; Step 2: Static aging: The mixture in step 1 is kept static for 24 hours at a temperature not lower than 15°C; Step 3, compression molding: statically press the mixed material after constant temperature static in step 2 to obtain a compact; the static pressing pressure is 40 tons to 50 tons per compact; Step 4, sintering: placing the compact obtained in step 3 in an electric furnace for sintering, taking it out after cooling down, and obtaining a sintered wall material; the sintering system is: at a heating rate of 3°C / min, first heating from room temperature to 200°C and keeping warm for 4 hours, then heating to 600°C and keeping warm for 1 hour, then heating to 900°C and keeping warm for 1.5 hours, and then heating to the firing temperature of 1100°C~1200°C and keeping warm for 4 hours; the cooling system is: at a cooling rate of 10°C / min, first cooling from the firing temperature to 900°C and keeping warm for 1 hour, and then cooling to room temperature.

Images