阅读说明：本技术 一种钢渣与赤泥反应资源回收再利用新工艺及应用 (Novel process for recycling reaction resources of steel slag and red mud and application ) 是由 席君杰 兰昊 黄传兵 广守泉 张会峰 张伟刚 刘正发 李树森 安钢 刘云 张宇 于 2020-07-23 设计创作，主要内容包括：本发明涉及钢渣与赤泥固体废弃物处理领域,特别是涉及一种钢渣和赤泥组分回收铁及资源再生利用的工艺及应用。本发明主要包括如下步骤：在钢渣A中加入赤泥B,混合均匀得到混合物C,将混合物C温度升至1200℃～1600℃,在混合物C中加入还原剂D,待所述还原剂D与所述混合物C充分反应后,使铁水E与熔融渣F分离。熔融渣材F经后续处理后制备石油压裂陶粒砂、水泥、玻璃等。所述钢渣A可以是钢厂熔融钢渣或者其冷却后经粉碎后的钢渣；所述赤泥是指拜耳法赤泥；所述还原剂的组分主要为碳和二氧化硅,优选为碳化稻壳、煤矸石等同时含有碳和硅的材料；所述钢渣和赤泥的质量比为5:95～95:5。本发明工艺简单,是一种资源改性再生的绿色短流程工艺,充分实现赤泥与钢渣资源的综合利用。(The invention relates to the field of treatment of steel slag and red mud solid waste, in particular to a process for recycling iron and resources from steel slag and red mud components and application thereof. The invention mainly comprises the following steps: adding the red mud B into the steel slag A, uniformly mixing to obtain a mixture C, heating the mixture C to 1200-1600 ℃, adding the reducing agent D into the mixture C, and separating the molten iron E from the molten slag F after the reducing agent D and the mixture C fully react. And the molten slag material F is subjected to subsequent treatment to prepare petroleum fracturing ceramsite sand, cement, glass and the like. The steel slag A can be steel mill molten steel slag or steel slag which is cooled and then crushed; the red mud refers to Bayer process red mud; the reducing agent mainly comprises carbon and silicon dioxide, preferably comprises materials such as carbonized rice hulls and coal gangue which simultaneously contain carbon and silicon; the mass ratio of the steel slag to the red mud is 5: 95-95: 5. The invention has simple process, is a green short-flow process for resource modification and regeneration, and fully realizes the comprehensive utilization of red mud and steel slag resources.)

1. A new process for recycling reaction resources of steel slag and red mud and an application thereof comprise the following steps:

(1) adding the red mud B into the steel slag A, and uniformly mixing to obtain a mixture C;

(2) and (3) heating the mixture C to 1200-1600 ℃, adding a reducing agent D into the mixture C, and after the reducing agent D and the mixture C are fully reacted, forming a glass material (sodium silicate, so that the pollution of the alkalization degree of the red mud is solved, and the cement building material is free of alkaline pollution). Meanwhile, air is isolated in the mixture, so that a reducing agent (such as carbon) can fully reduce iron elements, and the molten iron E is separated from the molten slag F, thereby realizing iron recycling.

(3) The slag material F1 which is separated by taking steel slag as a main material and red mud as an auxiliary material is mainly dicalcium silicate, tricalcium silicate, silicon dioxide, aluminum oxide, magnesium oxide and the like, is a key material for preparing cement and ceramsite sand materials, and is cooled and crushed into particles after the modification material fully reacts with the red mud steel slag to prepare the cement and petroleum fracturing ceramsite sand materials; or directly cooled into blocks, cut into building bricks, or added with foaming materials to prepare light heat-insulating bricks, etc., and has simple process and high strength.

(4) The glass can be made by adding water glass and other materials into the separated slag material F2 which takes the red mud as a main material and the steel slag as an auxiliary material.

2. The new process and application of recycling reaction resources of steel slag and red mud as claimed in claim 1, wherein said steel slag A can be molten steel slag of steel mill or steel slag obtained by cooling and crushing the molten steel slag. The molten steel slag obtained on line in the smelting process of a steel plant is preferably selected, and the iron is reduced by utilizing the reaction of the waste heat of the molten steel slag, the red mud and the reducing agent, so that a large amount of energy can be saved.

3. The new process and application of recycling reaction resources of steel slag and red mud according to claim 1, wherein the red mud refers to bayer process red mud, sintering process red mud, combination process red mud and the like.

4. The new process and application of recycling reaction resources of steel slag and red mud according to claim 1, wherein the reducing agent mainly comprises carbon and silicon dioxide, preferably comprises materials such as carbonized rice hulls and coal gangue which simultaneously contain carbon and silicon.

5. The new process and application of recycling of reaction resources of steel slag and red mud according to claim 1, wherein the mass ratio of steel slag to red mud is 5: 95-95: 5.

6. The new process and application of recycling of reaction resources of steel slag and red mud as claimed in claim 1, wherein the mass ratio of the reducing agent to the steel slag and the red mud is 1: 95-30: 70.

7. The new process and application of recycling reaction resources of steel slag and red mud as claimed in claim 1, wherein the molten iron E is separated from the molten slag material F by physical method including but not limited to density separation and magnetic separation.

8. The new process and application of recycling reaction resources of steel slag and red mud according to claim 1, wherein the glass material can be used in the reduction of all metals such as steel slag, iron slag, zinc slag, copper slag and the like, and can also be used in the reduction of iron element in red mud.

Technical Field

In order to realize full-resource comprehensive utilization of the steel slag and the red mud, the invention provides a new process for recycling reaction resources of the steel slag and the red mud and application thereof.

Background

Steel slag is waste slag produced in the process of steel production. About 12 to 20 percent of steel slag is generated in the steel production process, and the steel slag is not effectively utilized for a long time. The steel slag piled up not only occupies limited land resources and pollutes water and soil, but also is a huge resource waste. With the increase of steel slag stockpiles every year, steel producers around the world face the challenge of dealing with the problem under the current environmental requirements, and how to more reasonably utilize the advantages of steel slag components plays an especially important role in the sustainable development process of the whole steel industry in the comprehensive recycling of the steel slag.

The steel slag contains a large amount of iron resources which mainly exist in 2 forms of metallic iron and iron oxide, wherein the iron resources account for 8% -10% and 7% -30% respectively, elementary substance iron with larger particles can be separated by magnetic separation, and nonmagnetic Fe O, Fe2O3 and a small part of elementary substance iron still exist in tailings after the magnetic separation. Directly abandoning the iron in the tailings is a great waste of resources, and the existence of the iron oxide can cause the wear resistance of the tailings to be poor, so that the tailings serving as raw materials of cement, ceramics and the like are limited in the application process.

In order to create better economic and environmental benefits, a reasonable circular treatment process is selected in the steel industry, and the development of the recycling value of the steel slag is necessary and urgent, so that the method has great practical significance for saving enterprise resources, reducing environmental pollution and increasing the economic benefits of enterprises.

Red mud is a strong alkaline solid waste discharged from alumina production, and is called red mud because it contains a large amount of iron oxide, often red. According to the production method, the red mud can be divided into 3 types of Bayer process red mud, sintering process red mud and combination process red mud. 1.0-1.8 tons of red mud are generated per 1 ton of alumina, the global cumulative discharge of red mud exceeds 40 hundred million tons, and the annual discharge amount is increased by 1.2 million tons. However, China is a big country for discharging red mud, about 6000 million tons of red mud are discharged every year, the utilization rate of the red mud is very low, and most of the red mud is stockpiled by building a dam. The low-cost and harmless massive digestion and utilization of the red mud is a worldwide problem to be solved urgently. The stacking of the red mud wastes land resources, and due to the high alkalinity of the red mud, chemical components of the red mud can also permeate into soil and underground water to seriously pollute the ecological environment around the red mud stacking site. The research on the comprehensive utilization of red mud at home and abroad mainly focuses on producing buildings, ceramics, adsorbing novel functional materials, recovering iron, aluminum, titanium, sodium, rare metals and the like. The reduction, the resource utilization, the harmlessness and the full component utilization of the red mud not only can solve the serious environmental pollution caused by the storage of the dangerous wastes, but also can relieve the predicament that the bauxite and the iron ore in China highly depend on import, and can meet the national important strategic demands of ecological civilization construction and resource safety supply guarantee.

The comprehensive utilization and treatment of the red mud have attracted the attention of scholars, and a great deal of research work has been done by the former, but due to the special properties of the red mud, the comprehensive utilization of the red mud still has many problems. For example, as a structural material, red mud has a high alkali content, and when used as a building material, the red mud causes a blooming phenomenon, which affects the performance and the appearance of the red mud; the red mud is used as an adsorbent to treat sewage, and because the red mud contains heavy metal ions, the heavy metals in the red mud are possibly dissolved into water to cause secondary pollution; and the recovery of valuable metals therein has high cost.

Therefore, in order to realize the full-resource comprehensive utilization of the steel slag and the red mud, the invention provides a new process for recycling the reaction resources of the steel slag and the red mud and an application thereof. The utilization of the high-temperature waste heat of steel slag in a steel mill and the use of the red mud as an additive in the process of co-reduction of the steel slag are a new way for comprehensive utilization of the red mud. The steel mill steel slag waste heat is used as a heat source for reduction, so that the efficiency and the energy are high; the alkaline substances in the red mud are used for replacing additives in the reduction process of the steel slag, and the steel slag and the iron in the red mud are recovered; the reduction cost is reduced by utilizing the synergistic effect of reducing agents such as carbonized rice hulls and the like and the red mud; the glass film generated on the surface of molten steel in the high-temperature reaction process is utilized, so that air entering the steel slag reduction process is reduced, and the oxidation of iron in the reduction process is reduced; the reduced slag material can be used for preparing high-quality materials and realizing full-resource comprehensive utilization.

Disclosure of Invention

In view of the above disadvantages of the prior art, the present invention provides a new process for recycling reaction resources of steel slag and red mud and an application thereof, comprising the following steps:

(1) adding the red mud B into the steel slag A, and uniformly mixing to obtain a mixture C;

(2) and (2) heating the mixture C to 1200-1600 ℃, adding a reducing agent D into the mixture C, after the reducing agent D and the mixture C fully react, forming a glass material (a sodium silicate material to solve the strong alkaline pollution of the red mud), insulating air in the mixture at the same time, fully reducing the reducing agent (such as carbon) to obtain iron elements, and separating molten iron E from molten slag F to realize iron recycling.

(3) The slag material F1 which is separated by taking steel slag as a main material and red mud as an auxiliary material is mainly dicalcium silicate, tricalcium silicate, silicon dioxide, aluminum oxide, magnesium oxide and the like, is a key material for preparing cement and ceramsite sand materials, and is cooled and crushed into particles after the modification material fully reacts with the red mud steel slag to prepare the cement and petroleum fracturing ceramsite sand materials; or directly cooled into blocks, cut into building bricks, or added with foaming materials to prepare light heat-insulating bricks, etc., and has simple process and high strength.

(4) The glass can be made by adding water glass and other materials into the separated slag material F2 which takes the red mud as a main material and the steel slag as an auxiliary material.

The steel slag A can be steel mill molten steel slag or steel slag which is cooled and then crushed. The molten steel slag obtained on line in the smelting process of a steel plant is preferably selected, and the iron is reduced by utilizing the reaction of the waste heat of the molten steel slag, the red mud and the reducing agent, so that a large amount of energy can be saved.

The red mud refers to Bayer process red mud, sintering process red mud, combination process red mud and the like.

The reducing agent mainly comprises carbon and silicon dioxide, and preferably comprises materials such as carbonized rice hulls, coal gangue and the like which simultaneously contain carbon and silicon.

The mass ratio of the steel slag to the red mud is 5: 95-95: 5.

The mass ratio of the reducing agent to the steel slag and red mud is 1: 95-30: 70.

The molten iron E and the molten slag material F are separated by adopting a physical method to directly separate iron, and the physical method comprises but is not limited to processes of density separation, magnetic separation and the like.

The glass material can be independently used in the reduction reaction of all metals such as steel slag, iron slag, zinc slag, copper slag and the like, and can also be independently used in the reduction of iron element in red mud.

In the step 1, the temperature may be raised while the modifying material is fed, or the temperature may be raised after the modifying material is fed.

The modified materials are all products which can be directly bought in the market. The main components of carbonized rice husk, carbonized coconut shell and the like are carbon and silicon dioxide, and the price is low, the properties are stable, and the products are easy to purchase and use.

Adding a proper modified material into molten steel slag, separating molten iron from molten slag by using the waste heat of the molten steel slag, then discharging the molten iron, reducing iron resources in the steel slag by modifying and reconstructing components of the steel slag, and converting Ca, O and other substances in the steel slag into silicate to form the steel slag modified material. The steel slag with extremely low value is changed into iron, steel slag cement, ceramsite sand in the petroleum industry and the like, so that the added value of the steel slag is greatly improved, and a new profit growth point is found for domestic steel plants.

Advantageous effects

The invention provides a new process and application for recycling reaction resources of steel slag and red mud. The steel mill steel slag waste heat is used as a heat source for reduction, so that the efficiency and the energy are high; the alkaline substances in the red mud are used for replacing additives in the reduction process of the steel slag, and the steel slag and the iron in the red mud are recovered; the reduction cost is reduced by utilizing the synergistic effect of the carbonized rice hulls and the red mud; the glass film generated on the surface of molten steel in the high-temperature reaction process is utilized, so that air entering the steel slag reduction process is reduced, and the oxidation of iron in the reduction process is reduced; the reduced slag can be used for preparing high-quality glass and cement, and full-resource comprehensive utilization is realized.

Detailed Description

The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention.