阅读说明：本技术 一种烧结棕刚玉的湿法生产工艺 (Wet production process of sintered brown corundum ) 是由 黄道伦 于 2018-05-28 设计创作，主要内容包括：本发明公开一种烧结棕刚玉的湿法生产工艺,其以高铝矾土和氧化铝作为主原料,按重量百分比在容器中加入65％～80％高铝矾土和45～65％氧化铝,再加入结合剂及主原料重量0.8～1.0倍的水后,密封研磨得泥浆a,控制泥浆a中颗粒的粒度600目筛余小于0.5％；泥浆a经脱水、成型、烘干和煅烧即得。本工艺改变了传统采用干法生产烧结棕刚玉的方法,工艺能耗低,生产所得烧结棕刚玉产品中氧化铝含量97％以上,品质优良。(the invention discloses a wet production process of sintered brown fused alumina, which takes high-alumina bauxite and alumina as main raw materials, 65-80 percent of high-alumina bauxite and 45-65 percent of alumina are added into a container according to the weight percentage, a binding agent and water which is 0.8-1.0 time of the weight of the main raw materials are added, sealing and grinding are carried out to obtain slurry a, and the granularity of particles in the slurry a is controlled to be 600 meshes and the residual is less than 0.5 percent; and dehydrating, forming, drying and calcining the slurry a to obtain the catalyst. The process changes the traditional method for producing the sintered brown corundum by adopting a dry method, has low process energy consumption, and the alumina content in the produced sintered brown corundum product is more than 97 percent and has excellent quality.)

1. The wet production process of sintered brown corundum features that high-alumina and alumina as main material includes the following steps:

(1) adding 65-80% of high-alumina bauxite and 45-65% of alumina into a container according to the weight percentage, adding a binding agent and water which is 0.8-1.0 time of the weight of the main raw material, and then carrying out sealed grinding to obtain slurry a, wherein the granularity of particles in the slurry a is controlled to be less than 0.5% after a 600-mesh sieve;

(2) and (3) dehydrating: dehydrating the slurry a in a filter press to obtain a slurry cake b;

(3) molding: carrying out vacuum pugging on the mud cake b by using a vacuum mud extruder, extruding and cutting to form a mud section c;

(4) Drying: sending the mud segment c to a dryer for drying to obtain mud material d;

(5) And (3) calcining: and calcining the pug d in a kiln to obtain the sintered corundum.

2. the wet process for producing sintered brown fused alumina as claimed in claim 1, wherein the high bauxite grain size is not greater than 10 mm.

3. The wet process for producing sintered brown fused alumina according to claim 1, wherein the alumina is α -alumina and/or γ -alumina, and the alumina content is greater than 97%.

4. the wet process for producing sintered brown fused alumina as claimed in claim 1, wherein said binder is composed of polyaluminium chloride, polyvinyl alcohol and bentonite; the adding amount of the polyaluminium chloride is 0.2-0.4% of the weight of the main raw material, the adding amount of the polyvinyl alcohol is 0.1-0.15% of the weight of the main raw material, and the adding amount of the bentonite is 0.2-0.5% of the weight of the main raw material.

5. The wet process for producing sintered brown fused alumina according to claim 1, wherein in the step (2), the filter-pressing dewatering pressure of the filter-pressing machine is not more than 2.5 Mpa; and (4) in the step (3), the vacuum degree of the vacuum mud extruder is not less than 0.085 Mpa.

6. the wet production process of sintered brown fused alumina as claimed in claim 1, wherein the drying temperature in step (4) is 250-270 ℃ and the drying time is about 1.5 min.

7. the wet process for producing sintered brown fused alumina according to claim 1, wherein the calcination in step (5) is carried out in a rotary kiln under the conditions: the calcination temperature is 1750-1850 ℃, the heat preservation time is 13-18 min, and the total calcination time is 8-13 h.

Technical Field

the invention belongs to the technical field of refractory material production, and particularly relates to a wet production process for sintering brown corundum.

Background

With the continuous improvement of the performance requirements of the refractory materials, the usage proportion of the corundum with the alumina larger than 90 in the refractory materials is higher and higher. The used alumina is more than 90 corundum and mainly comprises fused corundum and sintered corundum, the fused corundum is prepared by smelting industrial alumina or bauxite serving as a raw material in an electric arc furnace at the temperature of 2000-2400 ℃, and the product cost is higher due to the large use of electric power.

The sintered brown corundum is sintered by adopting high-quality bauxite, but the bauxite is increasingly poor at present, the grade of the bauxite is integrally reduced, and the direct calcination by adopting high-grade ore is no longer possible. Therefore, not only the raw material cost is increased, but also the bauxite resource can not be reasonably used, and the high bauxite resource is greatly wasted.

Disclosure of Invention

The invention aims to provide a wet production process of sintered corundum, which has low energy consumption, and the obtained sintered brown corundum product has the alumina content of more than 97 percent and good quality.

in order to achieve the purpose, the invention adopts the following technical scheme:

1. The wet production process of sintered brown corundum features that high-alumina and alumina as main material includes the following steps:

(1) Adding 65-80% of high-alumina bauxite and 45-65% of alumina into a container according to the weight percentage, adding a binding agent and water which is 0.8-1.0 time of the weight of the main raw material, and then carrying out sealed grinding to obtain slurry a, wherein the granularity of particles in the slurry a is controlled to be less than 0.5% after a 600-mesh sieve;

(2) And (3) dehydrating: dehydrating the slurry a in a filter press to obtain a slurry cake b;

(3) molding: carrying out vacuum pugging on the mud cake b by using a vacuum mud extruder, extruding and cutting to form a mud section c;

(4) Drying: sending the mud segment c to a dryer for drying to obtain mud material d;

(5) and (3) calcining: calcining the pug d in a kiln to obtain sintered corundum;

2. The wet process for producing sintered brown fused alumina according to claim 1, wherein the high bauxite grain size is not greater than 10 mm;

3. the wet process for producing sintered brown fused alumina according to claim 1, wherein the alumina is α -alumina and/or γ -alumina, and the alumina content is greater than 98%.

4. The wet process for producing sintered brown fused alumina as claimed in claim 1, wherein said binder is composed of polyaluminium chloride, polyvinyl alcohol and bentonite; the adding amount of the polyaluminium chloride is 0.2-0.4% of the weight of the main raw material, the adding amount of the polyvinyl alcohol is 0.1-0.15% of the weight of the main raw material, and the adding amount of the bentonite is 0.2-0.5% of the weight of the main raw material;

5. the wet process for producing sintered brown fused alumina according to claim 1, wherein in the step (2), the filter-pressing dewatering pressure of the filter-pressing machine is not more than 2.5 Mpa; in the step (3), the vacuum degree of the vacuum mud extruder is not less than 0.085 Mpa;

6. The wet production process of sintered brown fused alumina as claimed in claim 1, wherein the drying temperature in the step (4) is 250-270 ℃, and the drying time is about 1.5 min;

7. the wet process for producing sintered brown fused alumina according to claim 1, wherein the calcination in step (5) is carried out in a rotary kiln under the conditions: the calcination temperature is 1750-1850 ℃, the heat preservation time is 13-18 min, and the total calcination time is 8-13 h.

compared with the prior art, the wet process has the following advantages:

(1) The wet process is adopted, the high-alumina bauxite and the alumina are added into a certain amount of water for wet mixing, and water molecules are diffused to a narrow area along the wall of a capillary tube or a microcrack of a material in grinding to generate pressure of about 0.1mpa on the four walls of the crack, so that the material is split and cracked more easily, and in addition, the raw materials can be promoted to be uniformly distributed.

(2) the compatibility of various binding agents such as polyaluminium chloride, polyvinyl alcohol and bentonite is adopted, so that the problems of low forming rate, low strength at low medium and high temperature and the like of wet forming materials are solved, and the formed mud segment in the wet production is not crushed or powdered in the transportation and sintering processes. And the added binding agent does not carry any impurity, so that the high-temperature use of the sintered corundum is not adversely affected, and the quality of the sintered corundum product is ensured.

(3) The vacuum pug mill is used for molding, so that the volume of air in pug is reduced to 0.5-0.8% from the original 7-10%, the composition is more uniform, the plasticity and the density are both increased, and the strength of a molded blank and the volume density after calcination are ensured.

(4) the corundum is calcined and sintered in the rotary kiln, so that the labor intensity is greatly reduced, and the operating environment is improved. In addition, the sintering temperature is uniform, and the phenomena of overburning and underburning are avoided.

(5) The corundum is fired by mixing alumina and bauxite ore, the content of the alumina is more than 97 percent, and the problems of large quality fluctuation, low grade, low utilization rate, unreasonable development and use and the like of the raw bauxite are thoroughly solved.

Detailed Description

the present invention is further illustrated by the following examples, but the scope of the present invention is not limited thereto. The technical parameters of polyaluminium chloride selected in the following examples: the content of alumina is more than or equal to 28 percent, and the pH value is 4.5-5.5; the average molecular weight of the selected polyvinyl alcohol is between 11 and 13 ten thousand.