CN110734317A

CN110734317A - Activating agent and method for leaching low-grade phosphorite in mechanochemical activation

Info

Publication number: CN110734317A
Application number: CN201911072792.2A
Authority: CN
Inventors: 王晨; 高宏; 应媛芳
Original assignee: LIAONING GEOLOGY ENGINEERING VOCATIONAL COLLEGE; Dalian Jiaotong University
Current assignee: LIAONING GEOLOGY ENGINEERING VOCATIONAL COLLEGE; Dalian Jiaotong University
Priority date: 2019-11-05
Filing date: 2019-11-05
Publication date: 2020-01-31

Abstract

The invention discloses activating agents, which consist of silicon dioxide and ammonium salt, are used for mechanochemical reaction of middle and low grade phosphorite and can greatly improve the leaching rate of the middle and low grade phosphorite.

Description

Activating agent and method for leaching low-grade phosphorite in mechanochemical activation

Technical Field

The invention relates to the technical field of mineral processing, in particular to activators and a method for leaching low-grade phosphorite in mechanochemical activations.

Background

China is of the world with the great phosphorus production and is also a country with the great consumption of phosphorus resources, the phosphorite resources of China are rich, the ascertained resources are second to Morocco and are second to the world, and the characteristics of concentrated ore resource distribution, more middle and low-grade ores, less high-grade rich ores, more difficultly selected ores, less easily selected ores, greater mining difficulty and the like are presented₂O₅Rich ore with the mass fraction of more than 30 percent is rapidly exhausted, and nearly 90 percent of phosphorite in China is middle-low grade phosphorite which is difficult to directly utilize, so that the comprehensive utilization of phosphorite resources is realizedThe method has the advantages of comprehensive utilization, improvement of the utilization rate of the middle-low grade phosphorite, attack of the pretreatment technology of the middle-low grade phosphorite, exploration and research of the effective utilization technology of the middle-low grade phosphorite powder, full utilization of phosphorus in the phosphorite, promotion of the release of the phosphorus, and realization of the fertilizer efficiency of the chemical phosphate fertilizer close to that of the chemical phosphate fertilizer with the same physical quantity, and has very important significance for full utilization of phosphorite resources in China.

At present, the treatment technology for using middle-low grade phosphate ore as phosphate fertilizer mainly includes acid method, thermal method and ball grinding method. The acid process for preparing phosphate fertilizer needs to consume large amount of inorganic acid (such as sulfuric acid, hydrochloric acid, nitric acid, etc.), and the obtained products are mainly various water-soluble phosphate fertilizers and phosphates, but the production of these phosphate fertilizers requires apatite containing P₂O₅More than or equal to 28 percent, the content and the granularity of impurities also meet the requirements of , the thermal method for preparing the phosphate fertilizer is generally used for producing calcium magnesium phosphate fertilizer, defluorinated phosphate fertilizer, sintered calcium sodium phosphate fertilizer and the like, taking the calcium magnesium phosphate fertilizer as an example, the phosphate fertilizer takes phosphorite and coke as raw materials, magnesium-containing silicate as a fluxing agent, the phosphate fertilizer is melted at the temperature higher than 1400 ℃, and then the melt is quenched in water, thus obtaining kinds of vitreous bodies containing magnesium oxide, calcium oxide, silicon oxide and phosphorus pentoxide, the ball milling method for preparing the phosphate fertilizer is to mill the phosphorite into phosphorite powder which is directly used as the fertilizer of acid soil, the milling fineness of the ore powder is required to be more than 100 meshes and more than 90 percent as , and the ore powder is required₂O₅The method comprises the steps of crushing raw materials into coarse phosphate ore powder through a crusher and a universal mill, crushing the coarse phosphate ore powder through a ball mill or a vibration mill to obtain superfine phosphate ore powder serving as a fertilizer premix, adding an additive and humic acid into the premix, performing high-energy activation treatment through a stirring mill or a vibration mill, and performing concentration granulation to obtain the superfine activated phosphate ore compound fertilizer product.

The mechanochemical reaction is to introduce mechanical energy accumulation through different action modes of mechanical force, such as grinding, compression, friction, impact, shearing, extension and the like, so that the physicochemical properties and the structure of a stressed object are changed, the reaction activity of the stressed object is improved, and the generated chemical reaction is excited and accelerated. The mechanical activation of the mineral is that the mineral generates lattice distortion and dislocation under the condition of mechanical action, and simultaneously the particle arrangement part in the lattice loses periodicity to form lattice defects, so that the internal energy of the lattice is increased, the surface performance is changed, the reaction activity is enhanced, and the leaching efficiency of the mineral is obviously improved. At present, no mechanochemical treatment scheme for the medium-low grade phosphorite is available.

Disclosure of Invention

In view of the defects and the requirements of the prior art, the invention aims to provide activators and methods for leaching low-grade phosphorite in mechanochemical activation.

According to an th aspect of an embodiment of the invention, there is provided an activator comprising of ammonium sulfate, ammonium chloride, ammonium bicarbonate, or a mixture thereof, mixed with silica, the molar ratio of ammonium ions to silica being 1: 2.

The activating agent is used for mechanochemical activation treatment of medium and low grade phosphorite, can greatly improve the leaching rate of the medium phosphorus element, has no corrosivity and no pollution, and effectively improves the utilization rate of the medium and low grade phosphorite.

The invention also provides a method for leaching kinds of low-grade phosphorite in mechanochemical activation, which comprises the following steps:

mixing the medium and low grade phosphorite with the activating agent to obtain a mixture, carrying out mechanical activation treatment on the mixture, roasting the mixture after the mechanical activation treatment, and finally leaching the roasted mixture by taking water as a solvent.

The method effectively improves the leaching rate and the utilization efficiency of the medium and low-grade phosphorite by processing the medium and low-grade phosphorite through mechanochemical reaction, is environment-friendly and pollution-free in the process, and improves the leaching rate of the medium and low-grade phosphorite by using the activating agent in steps.

In embodiments according to the invention, the mass ratio of the medium-low grade phosphate ore to the activating agent is 0-8: 1.

In embodiments according to the invention, the mechanical activation is achieved by:

and (3) treating for 1-15 min by adopting a high-energy planetary ball mill according to a ball-material ratio of 5-25: 1.

In embodiments according to the invention, the particle size of the mid-low grade phosphate ore is less than 1 mm.

In embodiments according to the invention, the temperature of the firing is 400-800 ℃.

In embodiments of the present invention, the solvent is deionized water, and the temperature of the solvent during leaching is 40-80 deg.C

It is to be understood that both the foregoing -general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification , illustrate embodiments consistent with the invention and together with the description , serve to explain the principles of the invention.

FIG. 1 is an XRD pattern of ground phosphate rock;

FIG. 2 is the XRD pattern after milling in example 2;

FIG. 3 is a graph comparing the effect of mechanical activation time on XRD of phosphate ore;

FIG. 4 is a comparison of XRD spectra of powdered rock phosphate ball-milled for 5min with activator, and powdered rock phosphate ball-milled for 5min without activator;

FIG. 5a is a SEM photograph of a raw ore;

FIG. 5b is a SEM photograph of the mixture after adding the activator and mixing and grinding;

FIG. 6 is a graph of the difference between the XRD of the product with the addition of the activators a, b, c, d, e and the result without the addition.

Detailed Description

The scope of embodiments of the invention includes the full ambit of the claims, as well as all available equivalents of the claims.

Example 1

10g of middle-low grade phosphate rock is subjected to mechanochemical activation, the ball-material ratio is 10:1, the grinding time is 5min after high-energy planetary ball milling, and the XRD (X-ray diffraction) spectrum of ground phosphate rock powder is shown in figure 2. Compared with the original middle-low grade phosphorite (the XRD spectrum is shown in figure 1), the phosphorite powder is mechanically activated when the ball-to-material ratio is 10:1, all diffraction peaks are reduced, particularly the diffraction peaks within the range of 2 theta more than 50 degrees indicate that the crystallinity is reduced, and the disorder degree is increased. The highest leaching rate of phosphorus is 10.9%.

Example 2

10g of middle-low grade phosphorite is subjected to mechanochemical activation, the ball-material ratio is 20:1, the grinding time is 15min by high-energy planetary ball milling, the ground phosphorite powder which is ground for 3min, 5min, 10min and 15min is respectively sampled and analyzed in the grinding, the XRD (X-ray diffraction) pattern of each sample is shown as figure 3, is caused by a diffraction peak of the initial middle-low grade phosphorite, but the diffraction peak of the fluorapatite is gradually reduced along with the increase of the mechanical activation time, namely the crystallinity is reduced, the disorder degree is increased, the diffraction peak is reduced to the minimum when the mechanical activation time is 5min, the mechanical activation time is prolonged, the diffraction peak is increased, possibly due to secondary particles, weak agglomeration is broken when the mechanical activation time is 15min, the diffraction peak agglomeration is reduced, then the circulation stage of weak agglomeration formation and breaking is carried out, the grinding is continued, the XRD pattern is not changed any more, the apatite is proved to be changed any more changed when the grinding is continued, and the change of the internal microstructure is only changed, so that the disorder degree of the phosphorite is the highest when the

Example 3

The mass ratio of the medium-low grade phosphate rock powder with the total mass of 10g to the activating agent is 3: 1, performing mechanochemical activation, wherein the ball-material ratio is 20:1, the ball milling time is 5 minutes, the XRD pattern is shown in figure 4, and the SEM picture is shown in figure 5 (figure 5a is raw ore, and figure 5b is a product after activation). Roasting the obtained mixed mineral powder at 600 ℃ for 3h, and then leaching in a water bath kettle, wherein the leaching temperature is 30 ℃, and the leaching rate is measured to be 45.8%.

Example 4

The mass ratio of the medium-low grade phosphate rock powder with the total mass of 10g to the activating agent is 4:1, performing mechanochemical activation, wherein the ball-material ratio is 20:1, the ball milling time is 5 minutes, roasting the obtained product at 600 ℃ for 3 hours, leaching the product in a water bath kettle for 1 hour, and the leaching temperature is 60 ℃, so that the leaching rate of the available phosphorus is 81.3 percent.

Example 5

The medium-low grade phosphorite with the total mass of 10g is respectively mixed with activating agents with different dosages, and the operation is carried out under various pellet-material ratios, roasting and leaching conditions, wherein the leaching rates are respectively shown in table 1:

TABLE 1 Leaching rate of middle and low grade phosphorus ore under different working conditions

From the above table, when the total mass of 10g of phosphate rock powder and the activating agent is 4:1, the ball-material ratio is 20:1, and the activation time of the high-energy ball mill is 5min, the obtained product is roasted at 600 ℃ for 3 hours and leached for 1 hour at 60 ℃, and the leaching rate of the available phosphorus is 81.3%.

Example 6

The medium and low grade phosphate rock powder with the total mass of 10g and a plurality of activators are mixed and activated according to the mass ratio of 4:1, as shown in figure 6, the XRD of the product added with the activators a, b, c, d and e is not much different from that of the product without the activators, and the particle size and the specific surface area of the product added with different activators under the conditions of wet grinding and dry grinding are measured and shown in tables 2 and 3.

TABLE 2 Dry grind particle size distribution

TABLE 3 Wet milling particle size distribution

From table 2, it is clear that the addition of these activators in the case of dry milling is not beneficial to both particle size and specific surface area, and from table 3, it is clear that the addition of sodium hexametaphosphate in the case of wet milling increases the specific surface area greatly, and finally it is found that the leaching rate of available phosphorus is 71.2%.

It is to be understood that the present invention is not limited to the procedures and structures described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the invention is limited only by the appended claims.

Claims

1, , activator silicon dioxide and ammonium salt, which is characterized in that the activator comprises of ammonium sulfate, ammonium chloride and ammonium bicarbonate or the mixture of the ammonium sulfate, the ammonium chloride and the ammonium bicarbonate and the silicon dioxide, wherein the molar ratio of ammonium ions to the silicon dioxide is 1: 2.

The method for leaching the medium-low grade phosphorite through the mechanical chemical activation is characterized by comprising the following steps:

mixing the medium and low grade phosphorite with the activating agent in claim 1 to obtain a mixture, carrying out mechanical activation treatment on the mixture, roasting the mixture after the mechanical activation treatment, and finally leaching the roasted mixture by using water as a solvent.

3. The method according to claim 2, wherein the mass ratio of the medium-low grade phosphate ore to the activating agent is 0-8: 1.

4. the method of claim 2, wherein the mechanical activation is achieved by:

5. The method of claim 2, wherein the particle size of the mid-low grade phosphate ore is less than 1 mm.

6. The method of claim 2, wherein the temperature of the firing is 400 to 800 ℃.

7. The method according to claim 2, wherein the solvent is deionized water, and the temperature of the solvent during leaching is 40-80 ℃.