Preparation process and system for producing high-grade titanium-rich material by utilizing ilmenite
阅读说明：本技术 一种利用钛铁矿生产高品位富钛料的制备工艺及系统 (Preparation process and system for producing high-grade titanium-rich material by utilizing ilmenite ) 是由 王雄 曾强 刘笃光 于 2020-08-28 设计创作，主要内容包括：本发明公开了一种利用钛铁矿生产高品位富钛料的制备工艺及系统,属于化工冶金领域,该工艺步骤如下：将钛铁矿精矿放入第一回转窑中,然后添加还原剂和脱硫剂进行一次还原得到还原料；将尾气依次通过高温旋风除尘,油气分离器,罗茨风机和气柜,最后将还原气体输送到第二回转窑中；将还原料冷却,然后通过筛分机和磁选机去除杂质,得到纯净粒度均匀的钛铁镶嵌物；送入第二回转窑中进行二次还原得到还原料；冷却,再依次进行磨选和磁选得到铁产品和富钛料。该工艺对于原料选料没有限制,设备故障率低,尾气处理简单,环保节能,且得到的铁产品的金属化率达到98%以上,富钛料的二氧化钛品味＞90%,其中颗粒目数、密度也达到产品要求。(The invention discloses a preparation process and a system for producing a high-grade titanium-rich material by utilizing ilmenite, belonging to the field of chemical metallurgy, and the process comprises the following steps: putting ilmenite concentrate into a first rotary kiln, and then adding a reducing agent and a desulfurizing agent for primary reduction to obtain a reduced material; the tail gas is sequentially subjected to high-temperature cyclone dust removal, an oil-gas separator, a Roots blower and a gas holder, and finally the reducing gas is conveyed into a second rotary kiln; cooling the reducing material, and then removing impurities through a sieving machine and a magnetic separator to obtain a ferrotitanium inlay with uniform pure granularity; sending the mixture into a second rotary kiln for secondary reduction to obtain a reducing material; cooling, and then sequentially carrying out grinding and magnetic separation to obtain an iron product and a titanium-rich material. The process has no limitation on raw material selection, low equipment failure rate, simple tail gas treatment, environmental protection and energy conservation, the metallization rate of the obtained iron product reaches more than 98 percent, the titanium dioxide taste of the titanium-rich material is more than 90 percent, and the particle mesh number and the density also reach the product requirements.)
1. A preparation process for producing a high-grade titanium-rich material by utilizing ilmenite is characterized by comprising the following specific process steps:
step 1, primary reduction: according to the mass percentage, 62-85% of ilmenite concentrate is placed into a first rotary kiln, then 14-35% of reducing agent and 1-3% of desulfurizing agent are added for primary reduction, the primary reduction temperature is controlled at 900-1150 ℃, the temperature is kept for 1-3h to obtain a reducing material, the pressure in the first rotary kiln is controlled to be not less than +2mm of water column, and CO/CO2The concentration ratio is more than 90 percent, and the oxygen content at the gas outlet is less than or equal to 5000 ppm;
step 2, tail gas treatment: the tail gas generated in the reduction process in the step 1 sequentially passes through a high-temperature cyclone dust removal device, an oil-gas separator, a Roots blower and a gas holder, and finally the reducing gas and the inert gas left in the gas holder are conveyed into a second rotary kiln through pipelines;
step 3, screening and magnetic separation: cooling the reducing material obtained in the step 1 to below 60 ℃, and then removing impurities through a screening machine and a first magnetic separator to obtain ferrotitanium inlays with uniform pure granularity;
and 4, secondary reduction: conveying the ferrotitanium mosaic obtained in the step 3 into a second rotary kiln through a pipeline for secondary reduction, controlling the temperature at 1150-1250 ℃, preserving the heat for 1-3h to obtain a reduced material, controlling the pressure in the second rotary kiln to be 0- +6mm water column, and controlling the oxygen content at an air outlet to be less than or equal to 1000 ppm;
step 5, grinding and magnetic separation: and (4) cooling the reduced material obtained in the step (4) to below 60 ℃, and then sequentially carrying out grinding and magnetic separation by a grinding and separating machine and a second magnetic separator to obtain an iron product and a titanium-rich material.
2. The process for preparing the high-grade titanium-rich material by utilizing the ilmenite as claimed in claim 1, wherein the content of the titanium dioxide in the ilmenite concentrate added in the step 1 is not less than 30%.
3. The process for preparing high-grade titanium-rich material by using ilmenite as claimed in claim 1, wherein the reducing agent in step 1 is one of bituminous coal, lignite and semi-coke; the desulfurizer is lime.
4. The process according to claim 1, wherein the metallization rate of iron in the reduced material obtained in step 1 is 80-96%.
5. The preparation process for producing the high-grade titanium-rich material by utilizing the ilmenite as claimed in claim 1, is characterized in that,the tail gas in the step 2 comprises water vapor, tar, dust, CO and H2、CO2A reducing gas and an inert gas.
6. The process for preparing high-grade titanium-rich material by using ilmenite as claimed in claim 1, wherein the impurities in the step 3 are low-melting-point inorganic substances, pulverized coal and non-magnetic substances; the titanium-iron inlay is metal particles with metal iron inlaid in titanium metal, wherein the content of the titanium-iron is more than or equal to 96 percent, and the content of inorganic matters with low melting point is less than 1 percent.
7. The preparation process for producing the high-grade titanium-rich material by utilizing the ilmenite as claimed in claim 1, wherein the heat source for reduction in the step 1 and the step 4 is electric heating, and the atmosphere is a reduction oxygen-insulating atmosphere.
8. The preparation process for producing the high-grade titanium-rich material by utilizing the ilmenite as claimed in claim 1, wherein the titanium-rich material obtained in the step 5 has the following quality requirements: the taste of the titanium dioxide is more than 90 percent, the particles with the number of 60-160 meshes account for more than 90 percent, and the density is more than or equal to 2.4kg/cm3。
9. The preparation system of the preparation process for producing the high-grade titanium-rich material by utilizing the ilmenite according to any one of claims 1 to 8, characterized by comprising the following steps of: a first rotary kiln (1), a second rotary kiln (2); the discharge end of the first rotary kiln (1) is conveyed to the feed end of the second rotary kiln (2) after passing through the sieving machine (3) and the first magnetic separator (4) in sequence, and gas in the first rotary kiln (1) is communicated with the cyclone dust collector (5), the oil-gas separator (6) and the Roots blower (7) in sequence through gas pipes and then communicated with the gas holder (8); the discharge end of the second rotary kiln (2) passes through a grinding and sorting machine (9) and a second magnetic separator (10) and then is discharged; and the gas holder (8) is communicated with the inside of the second rotary kiln (2) through a pipeline for supplying gas.
10. A production system according to claim 9, wherein the first and second rotary kilns (1, 2) comprise: the kiln comprises a kiln body (11), a roller (12) which rotates around a horizontal shaft in the kiln body (11), and a heating assembly (13) which is used for heating the roller (12) in the kiln body (11).
Technical Field
The invention belongs to the field of chemical metallurgy, and particularly relates to a preparation process and a system for producing a high-grade titanium-rich material by utilizing ilmenite.
Background
At present, more than 90% of ilmenite in the world is used for producing titanium white, about 4-5% of ilmenite is used for producing metallic titanium, and the rest is used for manufacturing welding electrodes, alloys, carbides, ceramics, glass, chemicals and the like. The titanium resource reserves in China are very rich, but the rutile in the main ilmenite is very little. The titanium ore in China is mainly produced by mining Guangdong, Guangxi, Hainan, Yunnan and Panzhihua in Sichuan, and the main product is ilmenite concentrate and also has a small amount of rutile concentrate. Because the grade of ilmenite concentrate is low, high-grade titanium-rich materials (high-titanium slag or artificial rutile) are usually obtained through enrichment treatment, and then the next treatment can be carried out.
The electric furnace smelting method is a mature titanium-rich material preparation method, the process is simple, the byproduct metallic iron can be directly utilized, the electric furnace gas can be recycled, the three wastes are less, the factory floor area is small, and the method is a high-efficiency smelting method. The electric furnace smelting method can obtain TiO2The high titanium slag with the content of about 80 percent is used as a raw material for the next treatment (such as acid leaching method or chlorination method). However, because the electric furnace smelting method belongs to high-temperature metallurgy, the high energy consumption is the inherent characteristic, about 3000kWh of electric energy is needed for producing 1 ton of high-titanium slag, and the chemical energy needed for reducing iron from ilmenite is only about 500kWh actually, namely, the effective utilization rate of the energy is only about 17 percent and is very low; secondly, the electric furnace smelting method uses metallurgical coke or petroleum coke as a reducing agent, and has certain environmental pollution.
The internal heating reduction rotary kiln is also a mature method for preparing the titanium-rich material, in the method, coal is not only a reducing agent but also serves as fuel, the temperature control in the whole process is controlled by the frequency conversion of a fan and the addition of pulverized coal, the reduction temperature is 1180 ℃, the temperature difference is +/-30 ℃, the metallization rate of iron is 92%, and the subsequent process generally adopts a corrosion method. The method has mature process, but has strict requirements on raw materials, the content of titanium dioxide is required to be more than 50 percent, the equipment maintenance and repair cost is high, coal is used as energy, a tail gas treatment system is huge, and the investment and the occupied area are large.
Disclosure of Invention
Aiming at the problems in the prior art, the invention aims to provide a preparation process for producing a high-grade titanium-rich material by utilizing ilmenite, which has no limitation on raw material selection, low equipment failure rate, simple tail gas treatment, environmental protection and energy conservation, and the metallization rate of the obtained iron product reaches more than 98 percent, the titanium dioxide taste of the titanium-rich material is more than 90 percent, wherein the particle mesh number and the density also meet the product requirements.
In order to realize the purpose, the invention adopts the technical scheme that:
a preparation process for producing a high-grade titanium-rich material by utilizing ilmenite comprises the following specific process steps:
and 4, secondary reduction: conveying the ferrotitanium mosaic obtained in the
Further, the content of titanium dioxide in the ilmenite concentrate added in the
Further, the reducing agent in the
Further, the metallization rate of iron in the reduced material obtained in the
Further, the tail gas in the
Further, the impurities in
Furthermore, the ferrotitanium mosaic obtained in the
Further, the heat source for reduction in the
Further, the quality requirements of the titanium-rich material obtained in the
The invention also provides a preparation system of the preparation process for producing the high-grade titanium-rich material by utilizing the ilmenite, which comprises the following steps: a first rotary kiln and a second rotary kiln; the discharge end of the first rotary kiln is conveyed to the feed end of the second rotary kiln after passing through the screening machine and the first magnetic separator in sequence, and gas in the first rotary kiln is communicated with the gas holder after sequentially passing through the cyclone dust collector, the oil-gas separator and the Roots blower through the gas pipe; the discharge end of the second rotary kiln discharges materials after passing through a grinding and separating machine and a second magnetic separator; and the gas holder is communicated with the interior of the second rotary kiln through a pipeline for supplying gas.
Further, the first rotary kiln and the second rotary kiln comprise: the kiln comprises a kiln body, a roller rotating around a horizontal shaft in the kiln body and a heating assembly used for heating the roller in the kiln body.
The invention has the beneficial effects that: (1) the process has no limitation on raw material selection, low equipment failure rate, simple tail gas treatment, environmental protection and energy conservation, the metallization rate of the obtained iron product reaches more than 98 percent, the titanium dioxide taste of the titanium-rich material is more than 90 percent, the particle mesh number and the density also reach the product requirements, namely the particles with the mesh number of 60-160 account for more than 90 percent, and the density is more than or equal to 2.4kg/cm3；
(2) In the primary reduction process, a low-temperature reduction process is adopted, the temperature is accurately controlled in an electric heating mode, and the reduction temperature is controlled to be below the melting point of a low-melting-point inorganic substance, so that the low-melting-point inorganic substance is not easy to melt, the ring formation phenomenon of a rotary kiln is avoided, the range is wider when raw materials are selected, and no special limitation is caused; in the reduction reaction, the iron element is reduced into elemental iron and carbon monoxide, and the elemental iron and the carbon monoxide are purified and then conveyed to the second rotary kiln to be used as a reducing agent for secondary reduction, so that the generated tail gas is effectively recycled, the effects of energy conservation and environmental protection are achieved, the gas-solid reaction can be directly carried out in the secondary high-temperature reduction, the reaction time is fast, and the ring formation phenomenon of the second rotary kiln is avoided;
(3) after primary reduction, inorganic substances with low melting point, coal dust and non-magnetic substances are separated from iron and titanium through screening and magnetic separation, so that ferrotitanium inlays with uniform pure particle size are further obtained, and the ring formation phenomenon caused by subsequent secondary reduction in a second rotary kiln is prevented;
(4) the invention adopts secondary high-temperature reduction, the metallic iron crystal grains embedded in titanium dioxide grow up at high temperature, so that the metallic iron and the titanium dioxide are easy to separate, the titanium iron inlay can be ground through simple grinding and selection, and then the titanium iron inlay and the titanium dioxide can be thoroughly separated through simple magnetic separation to obtain an iron product and a titanium-rich material respectively, therefore, the reduced material does not need to be crushed and pelletized, does not need to be ground, does not influence the granularity of the product, ensures that the obtained titanium-rich material has more than 90 percent of particles with the granularity of 60-160 meshes and the density of more than or equal to 2.4kg/cm3。
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.
FIG. 1 is a schematic layout of a manufacturing system according to an embodiment of the present invention;
FIG. 2 is a schematic side sectional view of the rotary kiln of FIG. 1 according to the present invention.
In the figure: 1. a first rotary kiln; 2. a second rotary kiln; 3. screening machine; 4. a first magnetic separator; 5. a cyclone dust collector; 6. an oil-gas separator; 7. a Roots blower; 8. a gas holder; 9. grinding and selecting machine; 10. a second magnetic separator; 11. a kiln body; 12. a drum; 13. and a heating assembly.
Detailed Description
For a better understanding of the present invention, embodiments of the present invention are described in detail below with reference to examples, but those skilled in the art will understand that the following examples are only for illustrating the present invention and should not be construed as limiting the scope of the present invention.
The ilmenite concentrates and compositions used in the following examples and comparative examples are as follows:
TABLE 1 imported ilmenite content of each component
TABLE 2 Panxi ilmenite content of each component
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