Phosphorus tailing filling material and application thereof

Abstract

The invention relates to the field of solid waste resource utilization, and discloses a phosphate tailing filling material and application thereof, the phosphate tailing filling material comprises phosphorite tailings and a consolidation agent which are independently preserved or preserved in a mixed manner; the weight ratio of the consolidation agent to the phosphorite tailings is 1: (6-10); the pH value of the phosphorite tailings is 4-6 under the condition that the mass ratio of the phosphorite tailings to the water is 2: 1; the fineness of the phosphorite tailings ranges from 100 meshes to 200 meshes; based on the total weight of the consolidation agent as 100 parts, the consolidation agent contains 40-80 parts of a first precursor material, 0-20 parts of a second precursor material, 5-20 parts of a sulfate material, 0-11 parts of an early strength agent and 1-12 parts of an exciting agent. The phosphate tailing filling material provided by the invention is excellent in early strength and later strength performance, the used raw materials are wide and easy to obtain, a large amount of industrial solid waste can be consumed, and the phosphate tailing filling material has good economical efficiency.

Description

Technical Field

[0001] The invention relates to the technical field of solid waste resource utilization, and in particular to a phosphate tailings filling material and an application thereof. Background Art

[0002] With the development of economy, green development of mining industry has become an inevitable trend. Processing tailings sand produced by mining with water and consolidating agent to form tailings filling material can not only effectively dispose of tailings sand and reduce environmental pollution caused by its accumulation, but also generate certain economic value and reduce filling cost, which is in line with the concept of green mine.

[0003] At present, cement is still the main binder in phosphate tailings filling. Although it has the characteristics of stable performance and wide sources, it has many problems in use, such as low early strength, slow coagulation, and excessive carbon emissions in the production process. In recent years, although there are other cementitious materials dedicated to the solidification of non-metallic tailings, these binders also have problems such as low strength or high cost in the solidification of phosphate tailings, and it is difficult to meet the current needs. With the improvement of mine filling requirements and the promotion of green and low-carbon in society, it is particularly important to make good use of phosphate tailings and develop a green, low-carbon, economical and high-strength phosphate tailings filling material. Summary of the invention

[0004] The purpose of the present invention is to overcome the defect that the phosphate tailings in the prior art cannot be effectively utilized and to provide a phosphate tailings filling material with high strength and low cost.

[0005] In order to achieve the above-mentioned object, the first aspect of the present invention provides a phosphate tailings filling material, which comprises phosphate tailings and a consolidating agent which are stored separately or mixed; the weight ratio of the consolidating agent to the phosphate tailings is 1:6-10; the pH value of the phosphate tailings is 4-6 under the condition that the mass ratio of the phosphate tailings to water is 2:1; the fineness of the phosphate tailings is between 100-200 meshes; Based on 100 parts of the total weight of the consolidating agent, the consolidating agent contains: 40-80 parts of the first precursor material, 0-20 parts of the second precursor material, 5-20 parts of the sulfate material, 0-11 parts of the early strength agent, and 1-12 parts of the activator; The first precursor material is selected from at least one of blast furnace slag powder, metakaolin, and steel slag powder; the second precursor material is selected from at least one of fly ash and sludge incineration ash.

[0006] The second aspect of the present invention provides a phosphate tailings filling slurry, which contains a phosphate tailings filling material and water, and the mass ratio of the phosphate tailings filling material to water is 2.0-2.5:1; the phosphate tailings filling material is the phosphate tailings filling material described in the first aspect.

[0007] The third aspect of the present invention provides the use of the phosphate tailings filling material described in the first aspect or the phosphate tailings filling slurry described in the second aspect in building materials.

[0008] The phosphate tailings filling material provided by the present invention has excellent early strength and late strength performance, uses a wide range of raw materials, is easy to obtain, can absorb a large amount of industrial solid waste, and has good economy.

[0009] The present invention uses phosphate tailings and a specific type of consolidating agent in combination to form a phosphate tailings filling material. Under the action of a specific proportion of sulfate materials and activators, the precursor material dissolves and condenses to form a large amount of hydrated gel, which has a good solidification effect on the phosphate tailings slurry. The solidification effect is far better than that of ordinary silicate cement early strength agents and other types of tailings solidification products, and can meet the application of phosphate tailings in different filling scenarios. DETAILED DESCRIPTION

[0010] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0011] For example, in the present invention, the fineness of phosphate tailings is 100-200 mesh, which means: phosphate tailings that can pass through a 100-mesh Chinese standard sieve but cannot pass through a 200-mesh Chinese standard sieve. Similar particle size expressions in the present invention have the same definition as this, and the present invention will not repeat them.

[0012] As mentioned above, the first aspect of the present invention provides a phosphate tailings filling material, which includes phosphate tailings and a consolidating agent that are stored separately or mixed; the weight ratio of the consolidating agent to the phosphate tailings is 1:6-10; Based on 100 parts of the total weight of the consolidating agent, the consolidating agent contains: 40-80 parts of the first precursor material, 0-20 parts of the second precursor material, 5-20 parts of the sulfate material, 0-11 parts of the early strength agent, and 1-12 parts of the activator; the pH value of the phosphate tailings is 4-6 under the condition that the mass ratio of the phosphate tailings to water is 2:1; the fineness of the phosphate tailings is between 100-200 meshes; The first precursor material is selected from at least one of blast furnace slag powder, metakaolin, and steel slag powder; the second precursor material is selected from at least one of fly ash and sludge incineration ash.

[0013] The inventors found in their research that by selecting phosphate tailings that meet this condition and using them in combination with the consolidating agent provided by the present invention, the gelling effect of the consolidating agent can be fully exerted, the active components in the consolidating agent can be fully stimulated, and a good solidification effect can be formed on the phosphate tailings. The solidification effect is far better than that of ordinary silicate early strength agents and other types of tailings solidification products, and can meet the application of phosphate tailings in different filling scenarios.

[0014] According to a preferred embodiment of the present invention, based on 100 parts of the total weight of the consolidating agent, the consolidating agent contains: 40-60 parts of the first precursor material, 0-20 parts of the second precursor material, 7-20 parts of the sulfate material, 3-11 parts of the early strength agent, and 1-10 parts of the activator.

[0015] Compared with other types of tailings, phosphate tailings have a lower pH value and contain some slow-setting substances such as apatite. Therefore, the existing solidifying cementitious materials on the market cannot play a good solidifying role on phosphate tailings, resulting in a large amount of phosphate tailings being accumulated and cannot be reasonably utilized. The phosphate tailings filling material provided by the present invention uses phosphate tailings that meet specific requirements in combination with a specific consolidating agent, overcomes the defect that phosphate tailings cannot be reasonably utilized, and obtains a phosphate tailings filling material with excellent early strength and late strength.

[0016] Preferably, the Blaine specific surface area of ​​the first precursor material is ≥350 m 2 / kg.

[0017] Preferably, the first precursor material is S95 grade blast furnace slag powder.

[0018] Preferably, the D90 value of the second precursor material is ≤75 μm, and the 28d activity index is ≥70%.

[0019] The 28d activity index detection method of the present invention refers to the national standard GB / T 1596-2017.

[0020] Preferably, the second precursor material is secondary fly ash and / or primary fly ash.

[0021] The S95 grade blast furnace slag powder described in the present invention refers to the mineral powder that meets the S95 grade requirements in the national standard GB / T 18046-2017; the secondary fly ash or primary fly ash described in the present invention refers to the fly ash that meets the secondary or primary requirements in the national standard GB / T 1596-2017.

[0022] The steel slag powder of the present invention refers to a fine powder formed by grinding the waste slag produced in the steel production process. The present invention preferably uses steel slag powder that meets the secondary requirements of the national standard GB / T 20491-2017.

[0023] The sludge incineration ash described in the present invention refers to the solid residue left after the sludge generated in the process of urban domestic sewage treatment is incinerated, and is a granular substance obtained after grinding.

[0024] According to a preferred embodiment of the present invention, the sulfate material is selected from at least one of natural anhydrous calcium sulfate, industrial grade anhydrous calcium sulfate, industrial grade calcium sulfate dihydrate, desulfurized gypsum, fluorinated gypsum, and phosphogypsum.

[0025] Preferably, the D90 value of the sulfate material is ≤150 μm.

[0026] Preferably, the SO3 content in the sulfate material is ≥45wt%.

[0027] Preferably, the early strength agent is selected from at least one of ordinary Portland cement, sulphoaluminate cement, aluminate cement and aluminum sulfate.

[0028] Preferably, the activator is selected from at least one of quicklime, carbide slag, calcium hydroxide, sodium silicate, phosphoric acid, and phosphate. The inventors found in their research that by selecting an activator that meets the preferred conditions and applying it to the phosphate tailings filling material, a phosphate tailings filling material product with better compressive strength can be obtained.

[0029] Preferably, the calcium hydroxide content of the carbide slag is ≥50wt%.

[0030] Preferably, the purity of the quicklime, the calcium hydroxide and the sodium silicate each independently satisfies ≥80%.

[0031] Preferably, the modulus of the sodium silicate is 1.0-1.6. The sodium silicate described in the present invention can be solid or liquid.

[0032] The modulus of the sodium silicate described in the present invention refers to the molar ratio of sodium oxide (Na2O) to silicon dioxide (SiO2) in the chemical formula.

[0033] As mentioned above, the second aspect of the present invention provides a phosphate tailings filling slurry, which contains phosphate tailings filling material and water, and the mass ratio of the phosphate tailings filling material to water is 2.0-2.5:1; the phosphate tailings filling material is the phosphate tailings filling material described in the first aspect above.

[0034] The present invention has no particular limitation on the specific preparation method of the phosphate tailings filling slurry, as long as the phosphate tailings filling material and water are evenly mixed. However, in order to obtain a gelling material with higher mechanical strength, the present invention preferably obtains the phosphate tailings filling slurry in the following manner.

[0035] According to a preferred embodiment of the present invention, the method for preparing the phosphate tailings filling slurry comprises: S1: first mixing the phosphate tailings in the phosphate tailings filling material with water to obtain a phosphate tailings slurry; S2: performing a second mixing of the phosphate tailings slurry and the consolidating agent to obtain the phosphate tailings filling slurry.

[0036] In the present invention, when preparing the phosphate tailings filling slurry, the phosphate tailings slurry can be obtained by mixing phosphate tailings with water, or can be phosphate tailings slurry directly produced after phosphate ore selection and washing. The present invention can directly utilize the phosphate tailings slurry waste generated in the phosphate ore selection and washing process, has simple material acquisition, and can absorb a large amount of industrial solid waste, thereby realizing comprehensive utilization of resources.

[0037] The present invention has no particular limitation on the specific operating conditions of the first mixing and / or the second mixing. Those skilled in the art can select the specific operating conditions according to technical means known in the art, as long as they can be mixed uniformly. The present invention will not go into details, and those skilled in the art should not interpret this as a limitation on the present invention.

[0038] As mentioned above, the third aspect of the present invention provides the use of the phosphate tailings filling material described in the first aspect or the phosphate tailings filling slurry prepared by the method described in the second aspect in building materials.

[0039] The present invention will be described in detail below by way of examples. In the following examples, unless otherwise specified, the raw materials are all commercially available.

[0040] Phosphate tailings 1: The pH value is 5.59 at a mass ratio of 2:1 with water; the fineness is between 100-200 mesh.

[0041] Phosphate tailings 2: The pH value is 4.83 when the mass ratio with water is 2:1; the fineness is between 200-300 mesh.

[0042] Phosphate tailings 3: The pH value is 3.53 when the mass ratio with water is 2:1; the fineness is between 100-200 mesh.

[0043] First precursor material: blast furnace slag powder: S95 grade, Blaine surface area of ​​413.3m 2 / kg.

[0044] First precursor material: steel slag powder: secondary steel slag powder, Blaine surface area of ​​378m 2 / kg.

[0045] Second precursor material: fly ash: secondary F class fly ash.

[0046] The second precursor material: sludge incineration ash: D90 value is 70μm, and 28d activity index is 71%.

[0047] Sulfate materials: phosphogypsum, D90 value is 138μm, SO3 content is 52.72wt%.

[0048] Sulfate materials: fluorinated gypsum, D90 value is 145μm, SO3 content is 50.91wt%.

[0049] Early strength agent: ordinary Portland cement: P·O42.5 grade cement.

[0050] Early strength agent: sulphoaluminate cement: C·SAC42.5 grade cement.

[0051] Activator: quicklime: industrial purity 90%.

[0052] Activator: carbide slag: calcium hydroxide content 91.7wt%.

[0053] Activator: Industrial grade powdered sodium silicate, purity above 90%, modulus 1.4.

[0054] Example 1 The phosphate tailings slurry containing phosphate tailings is stirred and mixed evenly with the components in the consolidating agent to obtain the phosphate tailings filling slurry; The amount of phosphate tailings used is 500g, wherein the concentration of phosphate tailings in the phosphate tailings slurry is 65wt%; the weight ratio of the consolidating agent to the phosphate tailings is 1:8.

[0055] The types and amounts of phosphate tailings and consolidating agents are listed in Table 1.

[0056] Example 2-Example 7 A similar process to Example 1 was adopted, except that the type and dosage parameters of each component were adjusted, as shown in Table 1, to prepare the phosphate tailings filling slurry.

[0057] Comparative Example 1 A similar process to Example 1 was adopted, except that the consolidating agent was replaced with an equal weight of 42.5 grade ordinary Portland cement, and the rest remained unchanged to prepare the phosphate tailings filling slurry.

[0058] Comparative Example 2 The process is similar to that of Example 1, except that the consolidating agent is replaced by an equal weight of non-metallic mine tailings filling cement powder (specific surface area of ​​430 m 2 / kg, purchased from Shandong Shunke Building Materials Technology Co., Ltd., named as glue powder), the rest remained unchanged to prepare the phosphate tailings filling slurry.

[0059] Comparative Example 3 A similar process to Example 1 is adopted, except that the phosphate tailings 1 is replaced by phosphate tailings 3 of equal weight, and the rest remain unchanged, to prepare the phosphate tailings filling slurry.

[0060] Comparative Example 4 A similar process to Example 1 is adopted, except that the phosphate tailings 1 is replaced by the phosphate tailings 2 of the same weight, and the rest remain unchanged, to prepare the phosphate tailings filling slurry.

[0061] Table 1

[0062] Table 1

[0063] Note: The types and amounts of the components in Table 1 correspond in order. For example, the type of activator is "quicklime + carbide slag" and the amount of activator is "3+5", which means that the amount of quicklime is 3 parts and the amount of carbide slag is 5 parts.

[0064] Test Case The phosphate tailings filling slurry obtained in the above-mentioned embodiments and comparative examples was cast into a cubic test block with a size of 40 mm×40 mm×40 mm, and cured in a curing box (curing conditions were 20°C±2°C, relative humidity ≥90%) to the corresponding age, and the uniaxial compressive strength of the test block was tested with a universal testing machine. The results are shown in Table 2.

[0065] Table 2

[0066] It can be seen from the above results that the phosphate tailings filling material provided by the present invention has excellent early strength and late strength performance, uses a wide range of raw materials, is simple to obtain, and can absorb a large amount of industrial solid waste, and has good economy. It also has a good solidification effect on the phosphate tailings slurry, and the solidification effect is far better than that of ordinary silicate early strength agents and other types of tailings solidification products, which can meet the application of phosphate tailings in different filling scenarios.

[0067] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A phosphate tailings filling material, characterized in that: The phosphate tailings filling material comprises phosphate tailings and a consolidating agent which are stored separately or mixed together; the weight ratio of the consolidating agent to the phosphate tailings is 1:6-10; the pH value of the phosphate tailings is 4-6 under the condition that the mass ratio of the phosphate tailings to water is 2:1; the fineness of the phosphate tailings is between 100-200 meshes; Based on 100 parts of the total weight of the consolidating agent, the consolidating agent contains: 40-80 parts of the first precursor material, 0-20 parts of the second precursor material, 5-20 parts of the sulfate material, 0-11 parts of the early strength agent, and 1-12 parts of the activator; The first precursor material is selected from at least one of blast furnace slag powder, metakaolin, and steel slag powder; the second precursor material is selected from at least one of fly ash and sludge incineration ash.

2. The phosphate tailings filling material according to claim 1, characterized in that: The Blaine specific surface area of ​​the first precursor material is ≥350m 2 / kg; And / or, the first precursor material is S95 grade blast furnace slag powder.

3. The phosphate tailings filling material according to claim 1 or 2, characterized in that: The D90 value of the second precursor material is ≤75 μm, and the 28d activity index is ≥70%; And / or, the second precursor material is secondary fly ash and / or primary fly ash.

4. The phosphate tailings filling material according to claim 1 or 2, characterized in that: The sulfate material is selected from at least one of natural anhydrous calcium sulfate, industrial-grade anhydrous calcium sulfate, industrial-grade calcium sulfate dihydrate, desulfurized gypsum, fluorinated gypsum, and phosphogypsum.

5. The phosphate tailings filling material according to claim 1 or 2, characterized in that: The D90 value of the sulfate material is ≤150 μm; And / or, the SO3 content in the sulfate material is ≥45wt%.

6. The phosphate tailings filling material according to claim 1 or 2, characterized in that: The early strength agent is selected from at least one of ordinary Portland cement, sulphoaluminate cement, aluminate cement and aluminum sulfate.

7. The phosphate tailings filling material according to claim 1 or 2, characterized in that: The activator is selected from at least one of quicklime, carbide slag, calcium hydroxide, sodium silicate, phosphoric acid and phosphate.

8. The phosphate tailings filling material according to claim 7, characterized in that: The calcium hydroxide content of the carbide slag is ≥50wt%; And / or, the purity of the quicklime, the calcium hydroxide and the sodium silicate independently satisfies ≥80%; And / or, the modulus of the sodium silicate is 1.0-1.

6.

9. A phosphate tailings filling slurry, characterized in that: The phosphate tailings filling slurry contains phosphate tailings filling material and water, and the mass ratio of the phosphate tailings filling material to water is 2.0-2.5:1; The phosphate tailings filling material is the phosphate tailings filling material according to any one of claims 1 to 8.

10. Use of the phosphate tailings filling material according to any one of claims 1 to 8 or the phosphate tailings filling slurry according to claim 9 in building materials.

Images