CN1041529C

CN1041529C - Process for refining and bleaching barite powder

Info

Publication number: CN1041529C
Application number: CN92103253A
Authority: CN
Inventors: 范蔚全; 王作霖
Original assignee: WUHAN GEOLOGICAL MANAGEMENT CADRE COLLEGE
Current assignee: WUHAN GEOLOGICAL MANAGEMENT CADRE COLLEGE
Priority date: 1992-04-29
Filing date: 1992-04-29
Publication date: 1999-01-06
Anticipated expiration: 2007-04-29
Also published as: CN1065874A

Abstract

The present invention provides whole production manufacturing technology for producing industrial filling material of barite powder (ISO3262 barite b grade) by using natural barite mineral resources. The technology is characterized in that barite raw ores are treated by a physical method to obtain micro powder-grade barite superfine raw material which is roasted into clinker under certain conditions. Base is removed by clear water, and dilute acid is used to wash the clinker. After the clinker is pulped, a certain sulphuric acid content and an aluminium powder dosage are controlled. The pulp is stirred to react at boiling temperature to obtain bleached material, and soluble salt is washed by clear water. The bleached material is dried and crushed to obtain a superthin white barite powder finished product. A manufacturer established by the technology of the present invention has low investment for establishing a plant. The present invention has the advantages of low product cost, less energy consumption and low environmental pollution.

Description

Method for micronizing and bleaching barite powder

The invention relates to a production process for manufacturing a b-grade product of barite according to the international organization for standardization 3262, in particular to a method for micronizing and bleaching barite powder.

The fine barite powder has wide application in the industrial departments of coating, paper making, rubber, printing ink and the like and the medical field. The traditional method for producing barium sulfate powder is a chemical method, the trade name of the product is precipitated barium sulfate, and the product is popular in industrial departments due to good service performance (small particles, low apparent specific gravity and high whiteness). However, the production process of precipitated barium sulfate is very complicated, the production cost is high, and the environmental pollution is difficult to treat, so that the production of ultra-fine barite powder by a physical-chemical method is very important at home and abroad at present. The powder has good dispersibility, high brightness after being prepared into a coating film, long storage period, and can replace a certain proportion of titanium dioxide in a white decorative high-grade coating after being processed to be superfine and high in whiteness.

The invention aims to provide a mineral resource using natural barite. The product produced by the method of the present invention can be used as a filler in industrial departments such as colored paint, rubber, printing ink, plastics, etc., and the product produced by the process of the present invention has the advantages of low cost, less investment in factory building and less environmental pollution.

The purpose of the invention is realized as follows: the method comprises the steps of processing barite raw ore by a physical method to obtain micron-sized barite raw material, and roasting under certain conditions to obtain clinker. Washing with clear water to remove alkalis (discharging and neutralizing the acidic waste water in the method at the same time), washing with dilute acid once, controlling the content of 100 g/l sulfuric acid and the dosage of 0.4% (weight percent) aluminum powder after pulping, and stirring and reacting at the boiling temperature for about 2.5 hours to obtain a bleaching material. Washing with clear water to remove soluble salts. Drying and crushing to obtain the high-fine white barite powder finished product. The specific method comprises the following steps:

1) the barite powder less than 43 microns is obtained after primary crushing of the barite raw ore. The 43 micron powder produced by barite raw ore is always used for drilling oil field, but about 15-20% (weight percentage)<15 micron powder is mixed in 43 micron powder and is detected to be wasted.

2) The grading point is positioned at 15 microns, and the barite powder raw material with the grain size less than 15 microns is obtained by separation through an airflow classifier. This step not only solves the problem of producing a high fine white powder feedstock in a submerged manner, but also improves the quality of the 43 micron powder as a weighting agent for petroleum drilling muds due to the removal of this fine powder (for<43 micron powder).

3) The raw material is roasted in a roasting furnace for 2 to 3 hours at the temperature of 830 ℃ and 890 ℃ to obtain the roasted clinker. The purpose of roasting the raw meal is two: one is to remove free carbon (a main factor influencing whiteness) contained in the raw materials, and the chemical reaction is as follows:

secondly, roasting carbonates, sulphidic minerals such as witherite (BaCO)₃) Limestone (CaCO)₃) Dolomite ([ Mg, Ca)]CO₃) Pyrite (FeS)₂) And the like, so that the oxide is converted into oxides which are convenient to process later. The main chemical reaction is as follows: (M represents an alkaline earth metal element)

4) Adding water, stirring and washing. The raw material is calcined to convert the carbonate into oxide. Most of which are soluble in large amounts of water as hydroxides. Through this step, part of impurities contained in the barite raw powder can be removed. And to make it consume no sulfuric acid. The chemical reaction formula is

5) Settling separation removes most of the water. The water separated by settling is strongly alkaline (pH>14). The water and the residual acid water in the subsequent step are discharged simultaneously to reach the sewage discharge standard meeting the regulations of environmental protection departments, thereby realizing environmental protection.

6) Adding diluted acid, stirring and pickling. The dilute acid can be prepared from the waste acid which is press-filtered from the reactor discharge, this step being not critical with respect to the concentration of acid and being essentially the dissolution of the partially insoluble hydroxides, such as, for example, Mg (OH)₂. Thus further removing impurities in the raw ore powder.

7) Settling separation removes most of the dilute acid. The dilute acid can be discharged simultaneously with the alkaline water in step 5) to achieve the purpose of neutralization.

8) And (4) pulping, wherein the density (g/cc) d = 1.3-1.8 of the pulp.

9)Pumping the slurry into a reaction kettle, adding sulfuric acid until the content is 100 g/l, adding aluminum powder according to the proportion of 0.4 percent (weight percent) of ore amount by four times, once every 30 minutes and 0.1 percent (weight percent) of each time, and reacting for 2.5 hours at the reaction temperature of 100 +/-5 ℃ to obtain the bleaching material.

10) Discharging and pumping into an acid-resistant filter press for pressure filtration to remove acid liquor. The acid liquor can be returned to the step 6) for use.

11) Washing with water to remove residual acid and iron ions.

12) Most of the water is removed by pressure filtration.

13) Drying on a drying bed and detecting the quality.

14) Crushing, drying and agglomerating to obtain the high-fine white barite powder.

15) And (6) packaging.

The high-fine white barite powder produced by the method can partially or completely replace precipitated barium sulfate and be used in industrial departments of papermaking (partial), paint (partial), plastics (complete), printing ink (complete), rubber (complete) and the like. Meanwhile, the main raw material barite powder adopted by the method is derived from waste materials generated in the process of producing 43-micron barite powder for oil field drilling, the used production equipment is simple and easy to arrange, the production steps are fewer, and the emission in the production process is easy to neutralize or recycle for preparation, so the method also has the advantages of low factory building investment and small environmental pollution. Low product cost, easy popularization and realization in areas with corresponding barite ore resources, and the like.

The process of the invention is further illustrated below with reference to examples:

1) producing 43 micron powder from barite raw ore by a jaw crusher and a Raymond mill;

2) utilizing an FQN-40 type internal circulation airflow classifier (power 3KW) to position a classification point at 15 microns so as to separate fine powder less than 15 microns to obtain a raw material for producing high-fine white barite powder;

3) roasting the raw material in a roasting furnace for 2.5 hours at 870 ℃ to obtain roasted clinker;

4) adding 5-6 times (volume ratio) of water, stirring and washing for 10 minutes;

5) settling and separating out most of water;

6) adding 5-6 times diluted acid (volume ratio), stirring and washing for 10 minutes; the dilute acid can be prepared by using the acid solution obtained by pressure filtering the discharged material from the reaction kettle in step 9);

7) settling and separating to remove most of dilute acid; discharging the alkaline water in step 5) at the same time.

8) Pulping until the pulp density (g/cubic centimeter) d = 1.6;

9) pumping the slurry into a reaction kettle, adding sulfuric acid until the content is 100 g/l, adding aluminum powder (the particle diameter = 0.84 mm) according to 0.4% (weight percent) of the ore amount in four times, stirring and reacting for 2.5 hours at 105 ℃ once every 30 minutes and 0.1% (weight percent) each time to obtain a bleaching material;

10) discharging and pumping into an acid-resistant filter press to remove acid liquor under pressure; the acid solution can be prepared into dilute acid for the step 6).

11) Adding water into the filter press to fully wash out residual acid and soluble salts until no iron ions are detected;

12) press filtering to remove most of water to obtain paste;

13) drying the paste material on a drying bed and detecting various quality indexes;

14) crushing, drying and agglomerating to obtain a finished product of high-fine white barite powder;

15) and (5) bagging the finished product.

Claims

1. A method for micronizing and bleaching barite powder comprises the following steps:

1) primarily crushing barite raw ore to obtain barite powder less than 43 microns;

2) the grading point is positioned at 15 microns, and the barite powder raw material with the grain size less than 15 microns is obtained by separation through an airflow classifier;

3) roasting the raw material in a roasting furnace for 2-3 hours at the temperature of 830-890 ℃ to obtain roasted clinker;

4) adding water, stirring and washing;

5) settling and separating to remove most of water;

6) adding diluted acid, stirring and washing;

7) settling and separating to remove most of dilute acid;

8) beating the slurry to make the density d = 1.3-1.8 g/cc;

9) pumping the slurry into a reaction kettle, adding sulfuric acid until the content is 100 g/l, adding aluminum powder into the reaction kettle four times according to the proportion of 0.4 percent of the ore weight, reacting for 2.5 hours at the reaction temperature of 100 +/-5 ℃ once every 30 minutes and about 0.1 percent of the ore weight at each time, and obtaining a bleaching material;

10) discharging and pumping into an acid-resistant filter press for pressure filtration to remove acid liquor;

11) washing with water to remove residual acid and iron ions;

12) filter pressing to remove most of water;

13) drying on a drying bed and detecting the quality;

15) and (6) packaging a finished product.