阅读说明：本技术 一种控制煅烧条件使煅烧磷矿合格的方法及系统 (Method and system for controlling calcination conditions to ensure qualified calcined phosphorite ) 是由 张建军 黄德明 华建青 刘法安 于 2018-08-31 设计创作，主要内容包括：本发明提供了一种控制煅烧条件使煅烧磷矿合格的方法,包括从燃料进料单元中提供燃料到煅烧单元,所述煅烧单元中包括回转窑；从磷矿进料单元提供磷矿到煅烧单元；所述燃料和磷矿在煅烧单元中的回转窑进行煅烧得到目标磷矿,根据燃料进料单元、磷矿进料单元以及煅烧单元来控制目标磷矿的品质为预设品质,所述预设品质是指目标磷矿中的氧化钙和氧化镁的总摩尔量与碳酸钙和碳酸镁的总摩尔量的比例为50-270∶1。本发明还提供一种控制煅烧条件使煅烧磷矿合格的系统。本发明提供的方法使得氧化钙和氧化镁的总摩尔量与碳酸钙和碳酸镁的总摩尔量的比例为50-270∶1,而这种比例的目标磷矿有利于在后续工艺中高效浸取钙和浸取镁离子。(The invention provides a method for controlling calcination conditions to ensure that phosphorite calcination is qualified, which comprises the steps of providing fuel from a fuel feeding unit to a calcination unit, wherein the calcination unit comprises a rotary kiln; providing phosphate ore from a phosphate ore feed unit to a calcination unit; and calcining the fuel and the phosphorite in a rotary kiln in the calcining unit to obtain target phosphorite, and controlling the quality of the target phosphorite to be preset quality according to the fuel feeding unit, the phosphorite feeding unit and the calcining unit, wherein the preset quality refers to that the ratio of the total molar weight of calcium oxide and magnesium oxide to the total molar weight of calcium carbonate and magnesium carbonate in the target phosphorite is 50-270: 1. The invention also provides a system for controlling the calcination condition to ensure that the calcined phosphorite is qualified. The method provided by the invention enables the ratio of the total molar amount of calcium oxide and magnesium oxide to the total molar amount of calcium carbonate and magnesium carbonate to be 50-270: 1, and the target phosphorite with the ratio is beneficial to efficiently leaching calcium and magnesium ions in subsequent processes.)

1. A method for qualifying calcined phosphate ore by controlling the calcination conditions, the method comprising:

providing fuel from a fuel feed unit to a calcination unit, wherein the calcination unit comprises a rotary kiln;

providing phosphate ore from a phosphate ore feed unit to a calcination unit;

and calcining the fuel and the phosphorite in a rotary kiln in a calcining unit to obtain target phosphorite, and controlling the quality of the target phosphorite to be preset quality according to the fuel feeding unit, the phosphorite feeding unit and the calcining unit, wherein the preset quality refers to that the ratio of the total molar weight of calcium oxide and magnesium oxide to the total molar weight of calcium carbonate and magnesium carbonate in the target phosphorite is 50-270: 1.

2. The method of claim 1, wherein the method further comprises:

the production efficiency of the target phosphate ore is also controlled to be a preset production efficiency according to the fuel feeding unit, the phosphate ore feeding unit and the calcining unit.

3. The method of claim 1, wherein the method further comprises:

and when the target phosphorite with preset quality is obtained, controlling the energy consumption of the fuel feeding unit to be lower than the preset energy consumption according to the phosphorite feeding unit and the calcining unit.

4. The method according to claim 1, wherein the rotary kiln is hollow cylindrical, the included angle between the rotary kiln and the plane is a preset angle, the rotary kiln comprises a phosphate ore feed port and a fuel feed port, the phosphate ore feed port is higher than the fuel feed port, phosphate ore enters the rotary kiln through the phosphate ore feed port and enters a calcination zone under the rotation of the rotary kiln, the calcination zone is located between the phosphate ore feed port and the fuel feed port, and the fuel enters the rotary kiln through the fuel feed port;

the "controlling the quality of the target phosphate ore to a preset quality according to the fuel feeding unit, the phosphate ore feeding unit, and the calcining unit" includes:

controlling the quality of target phosphorite to be preset quality according to the fuel feeding speed and the fuel quality of the fuel feeding unit, the phosphorite feeding speed and the phosphorite quality of the phosphorite feeding unit and the rotating speed of a rotary kiln in the calcining unit; the fuel quality is the combustion value of each kilogram of fuel, and the phosphorite quality is the weight content value of the phosphorus pentoxide in the phosphorite.

5. The method of claim 4, wherein the controlling the quality of the target phosphate ore to a predetermined quality according to the fuel feed unit, the phosphate ore feed unit, and the calcination unit comprises:

and controlling the quality of target phosphorite to be preset quality according to the fuel feeding speed and the fuel quality of the fuel feeding unit, the phosphorite feeding speed and the phosphorite quality of the phosphorite feeding unit, the rotating speed of a rotary kiln in the calcining unit and the specification parameters of the rotary kiln, wherein the specification parameters of the rotary kiln comprise the diameter of the rotary kiln, the length of the rotary kiln and a preset angle, and the phosphorite quality also comprises the ablation rate of the phosphorite.

6. The method as claimed in claim 5, wherein when the length of the rotary kiln is 18-22 m, the diameter is 1.3-1.7 m, the rotation speed is 4.5-5.5 Hz, the preset angle is 4-5 °, the fuel is pulverized coal, the combustion value of the pulverized coal is 4500-5500J/kg, the mass content of the phosphorus pentoxide in the phosphorus ore is 20-25%, and the ablation rate of the phosphorus ore is 16-20%;

the fuel feeding speed and the phosphorite feeding speed satisfy the following relational expression:

V₁＝(0.078-0.082)*V₂+K；

wherein V₁Is the fuel feed rate in tons/hour, V₂Is the phosphorite feed rate in tons/hour, where K is a constant and ranges from (-0.001) to 0.002.

7. The method of claim 6, wherein when the rotary kiln has a length of 20 meters, a diameter of 1.5 meters, a rotation speed of 5 hz, the pulverized coal has a combustion value of 4638 joules/kg, the phosphorus pentoxide content in the phosphorus ore is 22.69% by mass, and the ablation rate of the phosphorus ore is 18.22%;

the fuel feeding speed and the phosphorite feeding speed satisfy the following relational expression:

V₁＝0.08*V₂；

wherein V₁Is the fuel feed rate in tons/hour, V₂The unit is ton/hour, which is the phosphorite feeding speed.

8. The method of claim 4 wherein the lower the phosphate ore quality, the lower the phosphate ore feed rate when the rotary kiln is at a predetermined rotational speed, the fuel feed rate is at a predetermined fuel feed rate, and the fuel quality is at a predetermined fuel quality.

9. The method of claim 1, wherein the predetermined quality is that the ratio of the total molar amount of calcium oxide and magnesium oxide to the total molar amount of calcium carbonate and magnesium carbonate in the target phosphate ore is 60-180: 1.

10. A system for controlling calcination conditions to ensure that the calcined phosphorite is qualified is characterized by comprising a fuel feeding unit, a phosphorite feeding unit, a calcination unit and a control unit;

the fuel feed unit is used for providing fuel to the calcining unit, and the phosphorite feed unit is used for providing phosphorite to the calcining unit;

the calcining unit comprises a rotary kiln, and the fuel and the phosphorite are calcined in the rotary kiln to obtain target phosphorite;

the control unit is used for controlling the quality of the target phosphorite to be preset quality according to the fuel feeding unit, the phosphorite feeding unit and the calcining unit, wherein the preset quality refers to that the ratio of the total molar amount of calcium oxide and magnesium oxide to the total molar amount of calcium carbonate and magnesium carbonate in the target phosphorite is 50-270: 1, and preferably 60-180: 1.

Technical Field

The invention relates to the technical field of fertilizers, in particular to a method and a system for controlling calcination conditions to ensure that calcined phosphorite is qualified.

Background

Phosphorite is an important raw material mineral for producing phosphate fertilizer, yellow phosphorus, phosphoric acid and other various phosphatized products, is a double raw material of basic chemical industry and branch agriculture industry, and has important position and function in national economic development. Many of the current research on phosphate ore beneficiation processes focus on the subsequent leaching and purification of phosphate concentrate processes, and there is little research on the calcination conditions that will be used to calcine the raw ore to obtain a phosphate concentrate that is advantageous for subsequent leaching and purification.

The patent CN201410563330.1 provides a method for preparing a calcium magnesium nitrate fertilizer by using phosphate tailings, and the specific technical scheme is as follows: adding a certain amount of distilled water into a certain amount of tailing powder with a certain granularity to prepare tailing pulp with a certain solid content, gradually adding nitric acid, reacting under a certain condition, filtering after the reaction is finished, adding lime or calcium hydroxide into filtrate to adjust the pH value of the filtrate to 6.5-7, filtering again, and carrying out vacuum concentration drying on the filtrate to obtain the calcium magnesium nitrate fertilizer. The patent only discloses how to worth the calcium magnesium phosphate fertilizer and does not relate to controlling the calcination conditions.

ZL201510226362.7 patent provides a method for processing middle-low grade phosphorite to remove calcium and magnesium impurities in the middle-low grade phosphorite, which comprises the steps of calcining the middle-low grade phosphorite serving as a main raw material at 900-1100 ℃, sequentially digesting calcined slag with water at 60-100 ℃, leaching with an ammonium nitrate solution, and finally leaching with an ammonium sulfate solution to obtain phosphate concentrate, wherein calcium oxide and calcium and magnesium elements in the calcined slag can be effectively separated, and the content of phosphorus pentoxide in the phosphate concentrate can be improved. This patent also discloses only calcination temperature conditions, and does not relate to controlling other conditions, nor to the requirement of raw material quality for the leaching process.

CN107697894A and CN107673320A also only disclose particle size of calcined phosphate ore and do not relate to the requirement of raw material quality for leaching processes.

Disclosure of Invention

In view of the above, the invention provides a method capable of controlling the calcination conditions to ensure that the calcined phosphorite is qualified. The specific technical scheme is as follows.

A method for qualifying a calcined phosphate ore by controlling the calcination conditions, the method comprising:

providing fuel from a fuel feed unit to a calcination unit, wherein the calcination unit comprises a rotary kiln;

providing phosphate ore from a phosphate ore feed unit to a calcination unit;

and calcining the fuel and the phosphorite in a rotary kiln in a calcining unit to obtain target phosphorite, and controlling the quality of the target phosphorite to be preset quality according to the fuel feeding unit, the phosphorite feeding unit and the calcining unit, wherein the preset quality refers to that the ratio of the total molar weight of calcium oxide and magnesium oxide to the total molar weight of calcium carbonate and magnesium carbonate in the target phosphorite is 50-270: 1.

Preferably, the method further comprises:

the production efficiency of the target phosphate ore is also controlled to be a preset production efficiency according to the fuel feeding unit, the phosphate ore feeding unit and the calcining unit.

Preferably, the method further comprises:

and when the target phosphorite with preset quality is obtained, controlling the energy consumption of the fuel feeding unit to be lower than the preset energy consumption according to the phosphorite feeding unit and the calcining unit.

Preferably, the rotary kiln is hollow and cylindrical, an included angle between the rotary kiln and the plane is a preset angle, the rotary kiln comprises a phosphate rock feed port and a fuel feed port, the phosphate rock feed port is higher than the fuel feed port, phosphate rock enters the rotary kiln through the phosphate rock feed port and enters a calcination area under the rotation of the rotary kiln, the calcination area is located between the phosphate rock feed port and the fuel feed port, and fuel enters the rotary kiln through the fuel feed port;

the "controlling the quality of the target phosphate ore to a preset quality according to the fuel feeding unit, the phosphate ore feeding unit, and the calcining unit" includes:

controlling the quality of target phosphorite to be preset quality according to the fuel feeding speed and the fuel quality of the fuel feeding unit, the phosphorite feeding speed and the phosphorite quality of the phosphorite feeding unit and the rotating speed of a rotary kiln in the calcining unit; the fuel quality is the combustion value of each kilogram of fuel, and the phosphorite quality is the weight content value of the phosphorus pentoxide in the phosphorite.

Preferably, the "controlling the quality of the target phosphate ore to a preset quality according to the fuel feeding unit, the phosphate ore feeding unit, and the calcining unit" includes:

and controlling the quality of target phosphorite to be preset quality according to the fuel feeding speed and the fuel quality of the fuel feeding unit, the phosphorite feeding speed and the phosphorite quality of the phosphorite feeding unit, the rotating speed of a rotary kiln in the calcining unit and the specification parameters of the rotary kiln, wherein the specification parameters of the rotary kiln comprise the diameter of the rotary kiln, the length of the rotary kiln and a preset angle, and the phosphorite quality also comprises the ablation rate of the phosphorite.

Preferably, when the length of the rotary kiln is 18-22 meters, the diameter is 1.3-1.7 meters, the rotating speed is 4.5-5.5 Hz, the preset angle is 4-5 degrees, the fuel is coal powder, the combustion value of the coal powder is 4500-5500J/kg, the mass content of the phosphorus pentoxide in the phosphorus ore is 20-25 percent, and the ablation rate of the phosphorus ore is 16-20 percent;

the fuel feeding speed and the phosphorite feeding speed satisfy the following relational expression:

V₁＝(0.078-0.082)*V₂+K；

wherein V₁Is the fuel feed rate in tons/hour, V₂Is the phosphorite feed rate in tons/hour, where K is a constant and ranges from (-0.001) to 0.002.

Preferably, when the length of the rotary kiln is 20 meters, the diameter is 1.5 meters, the rotating speed is 5 Hz, the combustion value of the coal powder is 4638 joules/kg, the mass content of the phosphorus pentoxide in the phosphorite is 22.69%, and the ablation rate of the phosphorite is 18.22%;

the fuel feeding speed and the phosphorite feeding speed satisfy the following relational expression:

V₁＝0.08*V₂；

wherein V₁Is the fuel feed rate in tons/hour, V₂The unit is ton/hour, which is the phosphorite feeding speed.

Preferably, when the rotating speed of the rotary kiln is a preset rotating speed, the fuel feeding speed is a preset fuel feeding speed, and the fuel quality is a preset fuel quality, the lower the quality of the phosphorite is, the lower the phosphorite feeding speed is.

Preferably, the preset quality means that the ratio of the total molar amount of calcium oxide and magnesium oxide to the total molar amount of calcium carbonate and magnesium carbonate in the target phosphorite is 60-180: 1.

The invention also provides a system for controlling the calcination condition to ensure that the calcined phosphorite is qualified, which comprises a fuel feeding unit, a phosphorite feeding unit, a calcination unit and a control unit;

the fuel feed unit is used for providing fuel to the calcining unit, and the phosphorite feed unit is used for providing phosphorite to the calcining unit;

the calcining unit comprises a rotary kiln, and the fuel and the phosphorite are calcined in the rotary kiln to obtain target phosphorite;

the control unit is used for controlling the quality of the target phosphorite to be preset quality according to the fuel feeding unit, the phosphorite feeding unit and the calcining unit, wherein the preset quality refers to that the ratio of the total molar amount of calcium oxide and magnesium oxide to the total molar amount of calcium carbonate and magnesium carbonate in the target phosphorite is 50-270: 1, and preferably 60-180: 1.

The invention has the beneficial effects that: according to the method for controlling the calcination condition to ensure that the calcined phosphorite is qualified, the ratio of the total molar quantity of the calcium oxide and the magnesium oxide to the total molar quantity of the calcium carbonate and the magnesium carbonate is 50-270: 1 by controlling the fuel feeding unit, the phosphorite feeding unit and the calcination unit, and the target phosphorite with the ratio is beneficial to efficiently leaching calcium and magnesium ions in the subsequent process so as to obtain the phosphate concentrate with higher purity.

Drawings

FIG. 1 is a flow chart of the method for controlling the calcination conditions to ensure that the calcined phosphorite is qualified.

FIG. 2 is a schematic diagram of an apparatus for calcining phosphorus ore according to the present invention.

FIG. 3 is a sub-flow diagram of the phosphorite calcination process in step S300 of FIG. 1.

FIG. 4 is a block diagram of a system for controlling the calcination conditions to qualify the calcined phosphorus ore.

Detailed Description

While the following is a description of the preferred embodiments of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention.

Referring to fig. 1 and 2, the present invention provides a method for controlling the calcination conditions to qualify the phosphorite for calcination, which includes steps S100, S200 and S300. The steps are described in detail below.

Step S100, providing fuel from the fuel feeding unit 100 to the calcining unit 200, wherein the calcining unit 200 comprises a rotary kiln 210. It will be appreciated that the size and dimensions of the rotary kiln 210 may be set according to the actual throughput. It can be understood that the fuel includes but is not limited to one of pulverized coal, diesel oil, gasoline and natural gas, preferably, the fuel is pulverized coal, and the particle size and the combustion value of the pulverized coal are not limited, and more preferably, the particle size of the pulverized coal is 10-20mm, so that the pulverized coal can be rapidly combusted, high heat can be released, and the time for calcining the phosphate ore is saved. It will be appreciated that the fuel feed unit 100 includes a fuel feed detection unit for detecting the fuel feed rate.

In step S200, phosphate ore is provided from the phosphate ore feed unit 300 to the calcination unit 200. The phosphorite comprises various phosphorites with different qualities, such as high-grade (the phosphorus pentoxide content is more than 30 percent), medium-grade (the phosphorus pentoxide content is between 26 and 30 percent) phosphorite and low-grade (the phosphorus pentoxide content is less than 26 percent). It is understood that the phosphorite refers to the phosphorite obtained by primarily processing, crushing and screening raw phosphorite. Preferably, the particle size of the phosphorite is between 3 and 6mm, more preferably between 3.5 and 4.5mm, and the particle size range enables the phosphorite to be calcined better without increasing the crushing and screening process time. It is understood that the phosphate rock feeding unit 300 includes a feed hopper conveyor (not shown) for conveying phosphate rock and a phosphate rock feeding detection unit for detecting the feed rate of the phosphate rock.

And S300, calcining the fuel and the phosphorite in the rotary kiln 210 in the calcining unit 200 to obtain the target phosphorite, and controlling the quality of the target phosphorite to be preset quality according to the fuel feeding unit 100, the phosphorite feeding unit 300 and the calcining unit 200, wherein the preset quality refers to that the ratio of the total molar weight of calcium oxide and magnesium oxide to the total molar weight of calcium carbonate and magnesium carbonate in the target phosphorite is 50-270: 1. Preferably, the preset quality means that the ratio of the total molar amount of calcium oxide and magnesium oxide to the total molar amount of calcium carbonate and magnesium carbonate in the target phosphorite is 60-180: 1.

Phosphorus ore generally contains phosphorus salts, calcium carbonate, magnesium carbonate, sulfur, silicon, fluorine, and the like, and the phosphorus ore is calcined in the calcination unit 200 to remove mainly carbon dioxide, sulfur dioxide, fluorine, and the like. However, if the calcination condition cannot be controlled well, the phosphorite is over-burnt or under-calcined, which is not beneficial to the subsequent calcium-magnesium ion leaching process. When the phosphorite is over-burnt, namely the calcination time is too long or the calcination temperature is too high, the silicon in the phosphorite is over-burnt to sinter the phosphorite into blocks, which is not beneficial to the subsequent calcium and magnesium ion leaching process. When the phosphorite is not sufficiently calcined, it still contains a larger content of calcium carbonate and magnesium carbonate, which are disadvantageous for the subsequent calcium and magnesium ion leaching process compared with calcium oxide and magnesium oxide.

The method provided by the invention can obtain the ratio of the total molar amount of calcium oxide and magnesium oxide to the total molar amount of calcium carbonate and magnesium carbonate by controlling the fuel feeding unit 100, the phosphorite feeding unit 300 and the calcining unit 200, and the target phosphorite with the ratio is favorable for efficiently leaching calcium ions and magnesium ions in subsequent processes to obtain the phosphate concentrate with higher purity.

In a further embodiment, the method further comprises step S400.

Step S400, the production efficiency of the target phosphate ore is controlled to be a preset production efficiency according to the fuel feeding unit 100, the phosphate ore feeding unit 300 and the calcining unit 200. it is understood that the control can be performed by the fuel feeding speed of the fuel feeding unit 100, the phosphate ore feeding speed of the phosphate ore feeding unit 300 or the rotation speed of the rotary kiln 210, wherein the rotary kiln 210 rotates to convey the phosphate ore to the calcining zone 213, and after the completion of the calcining, the target phosphate ore continues to be conveyed to the cooling kiln by the rotation. it is understood that the rotary kiln 210 is provided with a rotation speed detecting unit 700 for detecting the rotation speed of the rotary kiln, wherein the rotation direction β of the rotary kiln 210 is shown in FIG. 2.

In a further embodiment, the method further comprises step S500.

In step S500, when the target phosphate ore having the preset quality is obtained, the power consumption of the fuel feeding unit 100 is also controlled to be lower than the preset power consumption according to the phosphate ore feeding unit 300 and the calcining unit 200. That is, the energy consumption of the fuel feeding unit 100 is minimized to save energy consumption, particularly, to reduce the amount of fuel, such as pulverized coal, while obtaining the target phosphate ore having a predetermined quality.

Referring again to fig. 2, in a further embodiment, the rotary kiln 210 is hollow and cylindrical, the angle between the rotary kiln 210 and the plane is a predetermined angle α, the rotary kiln 210 includes a phosphate ore feed port 211 and a fuel feed port 212, the phosphate ore feed port 211 is higher than the fuel feed port 212, the phosphate ore enters the rotary kiln 210 through the phosphate ore feed port 211 and enters a calcination zone 213 under the rotation of the rotary kiln 210, the calcination zone 213 is located between the phosphate ore feed port 211 and the fuel feed port 212, and the fuel enters the rotary kiln 210 through the fuel feed port 212, wherein the predetermined angle α is 4-6 °, preferably 4.5 °, after the phosphate ore enters the rotary kiln 210, the phosphate ore falls to the lowest part of the rotary kiln 210 due to the weight of the phosphate ore after the side wall of the rotary kiln 210 rises to a certain height under the rotation of the rotary kiln 210, and the rising height affects the calcination time of the phosphate ore in the rotary kiln 210.

The "controlling the quality of the target phosphate ore to a preset quality according to the fuel feeding unit 100, the phosphate ore feeding unit 300, and the calcining unit 200" includes:

controlling the quality of the target phosphate ore to be a preset quality according to the fuel feeding speed and the fuel quality of the fuel feeding unit 100, the phosphate ore feeding speed and the phosphate ore quality of the phosphate ore feeding unit 300, and the rotating speed of the rotary kiln 210 in the calcining unit 200; the quality of the fuel is the combustion value of each kilogram of fuel, and the quality of the phosphorite is the weight content value of the phosphorus pentoxide in the phosphorite. Wherein the fuel quality determines the amount of heat energy that the fuel can provide to the phosphate ore during combustion, the greater the combustion value, the greater the heat energy that is provided to the phosphate ore after combustion.

Referring to fig. 3 and 2, in a further embodiment, the "calcining the fuel and the phosphate ore in the rotary kiln 210 of the calcining unit 200 to obtain the target phosphate ore" includes steps S310 and S320. The detailed procedure is as follows.

In step S310, the phosphate ore is preheated in the preheating zone 214 of the rotary kiln 210 in the calcination unit 200. The preheating zone 214 is located between the calcination zone 213 and the phosphate rock feed inlet 211. The rotary kiln 210 is hollow, the heat generated by burning fuel and phosphorus ore is diffused along the periphery, when the phosphorus ore enters from the phosphorus ore feed inlet of the rotary kiln 210, the heat generated by burning in the calcining zone 213 is transferred to the preheating zone 214 to preheat the phosphorus ore, although the temperature does not reach the calcining temperature, the phosphorus ore can be heated, so that the phosphorus ore can be effectively calcined when reaching the calcining zone 213. If the phosphorus ore is not preheated, the temperature of the surface of the phosphorus ore is increased rapidly, the temperature of the interior of the phosphorus ore particles is increased slowly, and finally the calcination is not uniform.

In step S320, the fuel and the preheated phosphate ore are calcined in the calcining zone 213 of the rotary kiln 210. Wherein the fuel is preferably ignited and combusted above the calcination area 213, and the heat after combustion is transferred to the calcination area 213 to heat the phosphate ore, so as to calcine the phosphate ore. Compared with the contact combustion of fuel and phosphorite, the temperature of the fuel after ignition combustion is too high, and the risk of sintering and agglomeration caused by high-temperature and over-combustion of the phosphorite can be avoided. Wherein the temperature of the fuel after ignition and combustion is 1200-1500 ℃, and the temperature when the fuel is transferred to the calcining zone 213 is 900-1000 ℃ through heat transfer.

In a further embodiment, the "controlling the quality of the target phosphate ore to a preset quality according to the fuel feed unit 100, the phosphate ore feed unit 300, and the calcination unit 200" includes:

the quality of the target phosphorite is controlled to be preset quality according to the fuel feeding speed and the fuel quality of the fuel feeding unit 100, the phosphorite feeding speed and the phosphorite quality of the phosphorite feeding unit 300, the rotating speed of the rotary kiln 210 in the calcining unit 200 and the specification parameters of the rotary kiln 210, wherein the specification parameters of the rotary kiln 210 comprise the diameter of the rotary kiln, the length of the rotary kiln and a preset angle α, the phosphorite quality also comprises the ablation rate of the phosphorite, and the ablation rate refers to the weight content value lost by the phosphorite after calcining.

In a further embodiment, when the length of the rotary kiln is 18-22 meters, the diameter is 1.3-1.7 meters, the rotating speed is 4.5-5.5 Hz, the preset angle is 4-5 degrees, the fuel is coal powder, the combustion value of the coal powder is 4500-5500 joules/kg, the mass content of the phosphorus pentoxide in the phosphorus ore is 20-25 percent, and the ablation rate of the phosphorus ore is 16-20 percent;

the fuel feeding speed and the phosphorite feeding speed satisfy the following relational expression:

V₁＝(0.078-0.082)*V₂+K；

wherein V₁Is the fuel feed rate in tons/hour, V₂Is the phosphorite feed rate in tons/hour, where K is a constant and K isHas a value in the range of (-0.001) to 0.002.

In this embodiment, a large number of experiments prove that the fuel feeding speed and the phosphate rock feeding speed satisfy the relation V under the parameter conditions of the rotary kiln and the quality conditions of the coal powder and the phosphate rock₁＝(0.078-0.082)*V₂+ K. Through the relational expression, the two conditions in the relational expression can be adjusted when the phosphorite is calcined so as to obtain the calcined target phosphorite with preset quality, and further realize controllable calcining conditions.

In a further embodiment, when the length of the rotary kiln is 20 meters, the diameter is 1.5 meters, the rotating speed is 5 Hz, the fuel is coal powder, the combustion value of the coal powder is 4638 joules/kg, the mass content of the phosphorus pentoxide in the phosphorus ore is 22.69%, and the ablation rate of the phosphorus ore is 18.22%;

the fuel feeding speed and the phosphorite feeding speed satisfy the following relational expression:

V₁＝0.08*V₂；

wherein V₁Is the fuel feed rate in tons/hour, V₂The unit is ton/hour, which is the phosphorite feeding speed.

This embodiment provides a more accurate relationship and conditions for performing the relationship to provide more effective and precise control of the calcination of the phosphate ore.

Reference may be made specifically to the following specific example 1.

The following will illustrate, by way of specific example 1 and experimental data, that the fuel feed rate and the phosphate feed rate satisfy the relationship in the above example: v₁＝0.08*V₂In this case, the target phosphate ore having a predetermined quality can be obtained.