CN112250098A

CN112250098A - High-activity calcium oxide and preparation method thereof

Info

Publication number: CN112250098A
Application number: CN202011175697.8A
Authority: CN
Inventors: 童斌
Original assignee: Quzhou Shuntian Calcium Industry Co ltd
Current assignee: Quzhou Shuntian Calcium Industry Co ltd
Priority date: 2020-10-28
Filing date: 2020-10-28
Publication date: 2021-01-22

Abstract

The invention relates to the technical field of active lime production, and discloses high-activity calcium oxide and a preparation method thereof, wherein the preparation method of the high-activity calcium oxide comprises the following steps: s1, after limestone is selected, removing stones and partial impurities, screening by a crushing screening machine, and feeding screened limestone into a cylinder warehouse by a hoist; s2, mixing the screened limestone with anthracite coal in a certain proportion to form a mixture, and conveying the prepared mixture to a lifter by using a conveying belt so that the mixture is conveyed to the top of the lime kiln by the lifter. The preparation method provided by the invention effectively improves the activity of the calcium oxide, and can uniformly distribute heat on the powdery limestone by coating the inside of the lime kiln and matching with the spiral distributor, so that the reaction is uniformly heated, the yield and the quality of the active calcium oxide are improved, the heat preservation time is shortened, and the quality of the active calcium oxide is improved.

Description

High-activity calcium oxide and preparation method thereof

Technical Field

The invention relates to the technical field of active lime production, in particular to high-activity calcium oxide and a preparation method thereof.

Background

The active lime is a basic raw material in the steel industry, is also widely used in industries such as calcium carbide, electric power, glass fiber, building materials, papermaking, sewage treatment and the like, and the annual consumption is nearly billion tons. At present, the production methods of active lime at home and abroad are mainly three in nature, the first method is a production method which takes a vertical kiln as main roasting equipment, generally takes block limestone with the thickness of more than 20mm as a raw material and takes block coal as fuel; the second type is also a production method using lump limestone larger than 20mm as a raw material, but using combustible gas as a fuel, i.e., a so-called gas-fired kiln represented by a malz kiln; the third is a production method of the rotary kiln, in which the rotary kiln is a calcining kiln, a vertical preheater is arranged at the tail of the kiln, and a vertical cooler is arranged at the head of the kiln. At present, with the stricter and stricter environmental emission standards, the pollution treatment strength of the state is continuously increased, the emission standard of the cement kiln smoke is also stricter and stricter, and the requirement of the sulfur content of the cement kiln smoke is not higher than 50mg/m3 at present.

In recent years, powdered high-activity lime increasingly becomes a key basic material in the application aspect of high-new materials such as iron powder sintering, light building materials, chemical engineering and the like in China, and with the rapid increase of the domestic market demand and the continuous increase of environmental governance, the lime production industry faces huge pressure for eliminating backward capacity and updating production technology. Therefore, a simple and rapid production method of high-quality and high-activity calcium oxide is urgently needed to alleviate the dilemma.

Disclosure of Invention

Technical problem to be solved

Aiming at the defects of the prior art, the invention provides the high-activity calcium oxide and the preparation method thereof, which have the advantages of high activity, high production efficiency and waste reduction, meet the environmental protection requirement and solve the problems in the background art.

(II) technical scheme

In order to achieve the purpose, the invention provides the following technical scheme: the preparation method of the high-activity calcium oxide comprises the following steps:

s1, after limestone is selected, removing stones and partial impurities, screening by a crushing screening machine, and feeding screened limestone into a cylinder warehouse by a hoist;

s2, mixing the screened limestone with anthracite coal in a certain proportion to form a mixture, and conveying the prepared mixture to a lifter by using a conveying belt so that the mixture is conveyed to the top of a lime kiln by the lifter;

s3, uniformly stirring the mixture by a stirrer, so that the mixture enters a rotary distributor, and distributing the mixture in a lime kiln in a 360-degree rotary manner;

s4, calcining the mixture in a lime kiln at high temperature to form a primary product, keeping the primary product in a high-temperature state in the lime kiln to enable the primary product to be completely reacted, sending the primary product to a lifter through a disc ash discharger to enter a drum screen for screening, removing ash and coal cinder, entering a warehouse, conveying the primary product from the warehouse to a crusher for crushing, and finally entering the drum warehouse;

and S5, finally, conveying the primary product to a winnowing machine for grading winnowing, and grading and carefully selecting according to the product parameter requirements to obtain a finished product.

The crushing and screening machine in S1, comprising a feeding chamber, a crushing chamber and a screening chamber.

Preferably, the feeding chamber is arranged at the top end of the crushing chamber, the crushing chamber is arranged at the top end of the screening chamber, the top end of the feeding chamber is provided with a first motor, and the output end of the first motor is provided with a stirring rod, the bottom end of the stirring rod is fixedly connected with a blanking auger through a connecting piece, the left side and the right side of the outer wall of the crushing chamber are both provided with hydraulic rods, the other end of the hydraulic rod is connected with a base, the surface of the base is provided with a crushing roller, a first-stage filter plate and a second-stage filter plate are sequentially arranged in the screening chamber from top to bottom, and the bottom end of the screening chamber is provided with a vibrator, one end of the first-stage filter plate is connected with a first discharge hole arranged on one side of the screening chamber, and one side of a discharge port is connected with a sleeve, the top end of the sleeve is provided with a second motor, the output end of the second motor is connected with a feeding auger, and one end of the second-stage filter plate is connected with a second discharge port arranged on one side of the screening chamber.

Preferably, in S1: the calcium carbonate content of the limestone raw material is more than or equal to 54 percent, and the particle size of the screened limestone is as follows: 4-8 cm.

Preferably, in S4: the combustion temperature of the mixture in the lime kiln is not less than 1300 ℃, the time for the primary product to continuously keep a high-temperature state in the lime kiln is not less than 30 hours, and the crushing grain size of the primary product before entering the cylinder warehouse is 1 cm.

Preferably, the blanking auger is positioned in the bottom end opening end of the feeding chamber and extends to the inside of the crushing chamber.

Preferably, a feed inlet is formed in the top end of the feed chamber, a material guide pipe is communicated with one side of the top end of the sleeve, and one end of the material guide pipe is communicated with the feed inlet.

Preferably, the high-activity calcium oxide comprises the following components in percentage by weight: CaO is more than or equal to 95 percent, MgO is less than or equal to 1 percent, Fe is less than or equal to 0.05 percent, S is less than or equal to 0.15 percent, P accounts for less than or equal to 0.3 percent, AI2O3 is less than or equal to 0.5 percent, and CO2 is less than or equal to 3.0 percent.

(III) advantageous effects

Compared with the prior art, the invention has the following beneficial effects:

1. the preparation method provided by the invention effectively improves the activity of the calcium oxide, and can uniformly distribute heat on the powdery limestone by coating the inside of the lime kiln and matching with the spiral distributor, so that the reaction is uniformly heated, the yield and the quality of the active calcium oxide are improved, the heat preservation time is shortened, and the quality of the active calcium oxide is improved.

2. Through the crushing screening machine that sets up, can carry out efficient breakage and screening to the lime stone, distance between two crushing rollers of accessible hydraulic stem adjustment to can satisfy the broken demand of difference, through the one-level filter and the second grade filter that set up, improve the screening effect of likepowder lime stone, through the material loading auger that sets up, can carry out the secondary crushing screening with its particle diameter of lime stone that is greater than 8 centimeters, avoid the waste of raw materials, reduce manufacturing cost.

Drawings

FIG. 1 is a schematic flow chart of a method for preparing high-activity calcium oxide according to the present invention;

FIG. 2 is a schematic structural view of the crushing and screening machine of the present invention.

In the figure: 1. a feed chamber; 101. a first motor; 102. a stirring rod; 103. a blanking auger; 104. a feed inlet; 2. a crushing chamber; 201. a hydraulic lever; 202. a base; 203. a crushing roller; 3. a screening chamber; 301. a first-stage filter plate; 302. a secondary filter plate; 303. a vibrator; 304. a first discharge hole; 305. a sleeve; 306. a second motor; 307. a feeding auger; 308. a second discharge hole; 309. a material guide pipe.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

The preparation method of the high-activity calcium oxide in the embodiment comprises the following steps:

s1, after limestone with the content reaching the standard (not less than 54%) accounting for 95% of the limestone is selected, removing the limestone and partial impurities, screening the limestone with the granularity of 5 cm by a crushing and screening machine, feeding the limestone into a cylinder warehouse by a lifting machine, and sequentially conveying 1% of MgO, 0.05% of Fe, 0.15% of S, 0.3% of P, 0.5% of AI2O3 and 3% of CO2 into the cylinder warehouse;

s3, uniformly stirring the mixture by a stirrer, enabling the mixture to enter a rotary distributor, distributing the mixture in a 360-degree rotary manner to enter a lime kiln, and arranging a heat-insulating layer with the thickness of 4cm in the lime kiln;

s4, calcining the mixture in a lime kiln at 1300 ℃ to form a primary product, keeping the primary product in a high-temperature state for 30 hours in the lime kiln to enable the primary product to be completely reacted, then sending the primary product to a lifter to enter a drum screen for screening through a disc ash discharger, removing ash powder coal slag, then entering a warehouse, conveying the warehouse to a crusher for crushing with a particle size of 1 cm, and finally entering the drum warehouse;

Example 2

s1, after limestone with the content reaching the standard (not less than 54%) accounting for 95.16% is selected, removing the limestone and partial impurities, screening the limestone by a crushing and screening machine, feeding the limestone with the screened content of 5 centimeters into a cylinder warehouse by a lifting machine, and then sequentially conveying 1% of MgO, 0.04% of Fe, 0.1% of S, 0.2% of P, 0.5% of AI2O3 and 3% of CO2 to the cylinder warehouse;

s4, calcining the mixture in a lime kiln at a high temperature of 1200 ℃ to form a primary product, keeping the primary product in a high-temperature state for 30 hours in the lime kiln to enable the primary product to be completely reacted, then sending the primary product to a lifter through a disc ash discharging machine to enter a drum screen for screening, removing ash powder coal slag, then entering a warehouse, conveying the warehouse to a crusher for crushing with a particle size of 1 cm, and finally entering the drum warehouse;

Example 3

s1, after limestone with the content reaching the standard (not less than 54%) accounting for 95.32% is selected, removing the limestone and screening partial impurities by a crushing and screening machine, screening out limestone with the size of 5 centimeters, entering a cylinder warehouse by a lifting machine, and sequentially conveying 0.9% of MgO, 0.04% of Fe, 0.14% of S, 0.3% of P, 0.3% of AI2O3 and 3% of CO2 into the cylinder warehouse;

s4, calcining the mixture in a lime kiln at a high temperature of 1000 ℃ to form a primary product, keeping the primary product in a high-temperature state for 30 hours in the lime kiln to enable the primary product to be completely reacted, then sending the primary product to a lifter through a disc ash discharging machine to enter a drum screen for screening, removing ash powder coal slag, then entering a warehouse, conveying the warehouse to a crusher for crushing with a particle size of 1 cm, and finally entering the drum warehouse;

On the basis of embodiments 1, 2 and 3, please refer to fig. 1-2, S1, the crushing and screening machine includes a feeding chamber 1, a crushing chamber 2 and a screening chamber 3, the feeding chamber 1 is disposed at the top end of the crushing chamber 2, the crushing chamber 2 is disposed at the top end of the screening chamber 3, a first motor 101 is disposed at the top end of the feeding chamber 1, a stirring rod 102 is disposed at the output end of the first motor 101, the bottom end of the stirring rod 102 is fixedly connected with a blanking auger 103 through a connecting member, hydraulic rods 201 are disposed at the left and right sides of the outer wall of the crushing chamber 2, the other end of the hydraulic rod 201 is connected with a base 202, a crushing roller 203 is disposed on the surface of the base 202, a first-stage filter plate 301 and a second-stage filter plate 302 are sequentially disposed inside the screening chamber 3 from top to bottom, a vibrator 303 is disposed at the bottom end of the screening chamber 3, one end of the first-stage filter plate 301 is connected with, one side of the first discharge port 304 is connected with a sleeve 305, the top end of the sleeve 305 is provided with a second motor 306, the output end of the second motor 306 is connected with a feeding auger 307, one end of the second-stage filter plate 302 is connected with a second discharge port 308 arranged on one side of the sieving chamber 3, the discharging auger 103 is positioned in the bottom end opening end of the feeding chamber 1 and extends into the crushing chamber 2, the top end of the feeding chamber 1 is provided with a feeding port 104, one side of the top end of the sleeve 305 is communicated with a material guide pipe 309, one end of the material guide pipe 309 is communicated with the feeding port 104, the distance between the two crushing rollers 203 can be adjusted through the two hydraulic rods 201, thereby different crushing requirements can be met, the sieving effect of powdery limestone is improved through the arranged first-stage filter plate 301 and the second-stage filter plate 302, the particle size of limestone larger than 8 centimeters can be subjected to secondary crushing, avoid the waste of raw materials, reduce manufacturing cost.

The working principle is as follows: firstly, limestone enters a feeding chamber 1 through a feeding hole 104, a first motor 101 drives a stirring rod 102 and a blanking auger 103 to rotate, so that the limestone is conveniently and uniformly conveyed to the inside of a crushing chamber 2, two crushing rollers 203 crush the limestone, the crushed limestone falls onto a first-stage filter plate 301, a vibrating machine 303 filters and sieves the limestone, so that the filtered limestone powder moves from a second-stage filter plate 302 to a second discharge hole 308, the limestone with large particle size filtered by the first-stage filter plate 301 moves from the first discharge hole 304 to a sleeve pipe 305, the limestone with large particle size is conveyed into a material guide pipe 309 through a second motor 306, secondary crushing and sieving are carried out through the feeding hole 104, and finally the sieved limestone powder with 4-8 particle size is conveyed into a cylinder warehouse, so that the crushing and sieving machine use process is completed.

Group of	Calcium oxide yield (mg/g)	Degree of activity (mL)
			Example 1	989.56	495
Example 2	993.36	487
			Example 3	995.84	448

From the above table, the calcium oxide prepared by the following formula has the highest activity, CaO is more than or equal to 95%, MgO is less than or equal to 1%, Fe is less than or equal to 0.05%, S is less than or equal to 0.15%, P is less than or equal to 0.02%, and AI2O3 is less than or equal to 0.5%; CO2 ≦ 3%.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. A high-activity calcium oxide is characterized in that: the preparation method of the high-activity calcium oxide comprises the following steps:

The crushing and screening machine in the S1 comprises a feeding chamber (1), a crushing chamber (2) and a screening chamber (3).

2. The crushing and screening machine of S1, according to claim 1, wherein: the feeding chamber (1) is arranged at the top end of the crushing chamber (2), the crushing chamber (2) is arranged at the top end of the screening chamber (3), a motor (101) is arranged at the top end of the feeding chamber (1), a stirring rod (102) is arranged at the output end of the motor (101), the bottom end of the stirring rod (102) is fixedly connected with a blanking auger (103) through a connecting piece, hydraulic rods (201) are arranged on the left side and the right side of the outer wall of the crushing chamber (2), the other end of each hydraulic rod (201) is connected with a base (202), a crushing roller (203) is arranged on the surface of the base (202), a first-stage filter plate (301) and a second-stage filter plate (302) are sequentially arranged inside the screening chamber (3) from top to bottom, a vibrator (303) is arranged at the bottom end of the screening chamber (3), one end of the first-stage filter plate (301) is connected with a first discharge hole (304) arranged on one side of the, and one side of a first discharge port (304) is connected with a sleeve (305), the top end of the sleeve (305) is provided with a second motor (306), the output end of the second motor (306) is connected with a feeding auger (307), and one end of the second-stage filter plate (302) is connected with a second discharge port (308) arranged on one side of the screening chamber (3).

3. The method for preparing highly active calcium oxide according to claim 1, wherein: in said S1: the calcium carbonate content of the limestone raw material is more than or equal to 54 percent, and the particle size of the screened limestone is as follows: 4-8 cm.

4. The crushing and screening machine of S1, according to claim 1, wherein: in said S4: the combustion temperature of the mixture in the lime kiln is not less than 1300 ℃, the time for the primary product to continuously keep a high-temperature state in the lime kiln is not less than 30 hours, and the crushing grain size of the primary product before entering the cylinder warehouse is 1 cm.

5. The crushing and screening machine of S1, according to claim 1, wherein: the blanking auger (103) is positioned in the bottom end opening end of the feeding chamber (1) and extends to the inside of the crushing chamber (2).

6. The crushing and screening machine of claim 1, wherein: the feeding device is characterized in that a feeding hole (104) is formed in the top end of the feeding chamber (1), a material guide pipe (309) is communicated with one side of the top end of the sleeve (305), and one end of the material guide pipe (309) is communicated with the feeding hole (104).

7. The highly active calcium oxide according to claim 1, wherein: the high-activity calcium oxide comprises the following components in percentage by weight: CaO is more than or equal to 95 percent, MgO is less than or equal to 1 percent, Fe is less than or equal to 0.05 percent, S is less than or equal to 0.15 percent, P accounts for less than or equal to 0.3 percent, AI2O3 is less than or equal to 0.5 percent, and CO2 is less than or equal to 3.0 percent.