阅读说明：本技术 一种瓦斯灰和煤矸石全资源化协同利用的方法 (Full-resource cooperative utilization method for gas ash and coal gangue ) 是由 胡可 雷家柳 陈宇航 江昆 吴前龙 肖蒙蒙 蒋璇琪 于 2021-08-20 设计创作，主要内容包括：本发明涉及一种瓦斯灰和煤矸石全资源化协同利用的方法,具体包括以下步骤：(1)将瓦斯灰和煤矸石分别研磨至200目以上的粉末状,再配加一定量的粘结剂,按一定比例充分混匀后压成圆柱形混合压块；(2)将步骤(1)制得的混合压块进行干燥处理；(3)将步骤(2)中得到的混合压块放入到加热炉内,在1120～1360℃的温度下反应90～180 min,加热过程中持续向加热炉内通入氩气,或维持加热炉内一定的真空度,使反应在真空环境中反应完成；(4)将步骤(3)所得到的共还原产物经破碎、粉磨、磁选干燥得到硅铁合金粉,同时得到高氧化铝含量的尾渣；该方法可以在不加碳质还原剂的前提下,同步实现瓦斯灰和煤矸石的全资源化高附加值利用。(The invention relates to a full resource cooperative utilization method of gas ash and coal gangue, which specifically comprises the following steps: (1) grinding the gas ash and the coal gangue to powder with more than 200 meshes respectively, adding a certain amount of binder, fully and uniformly mixing according to a certain proportion, and pressing into a cylindrical mixed pressing block; (2) drying the mixed briquettes prepared in the step (1); (3) putting the mixed pressing block obtained in the step (2) into a heating furnace, reacting for 90-180 min at the temperature of 1120-1360 ℃, and continuously introducing argon into the heating furnace in the heating process or maintaining a certain vacuum degree in the heating furnace to complete the reaction in a vacuum environment; (4) crushing, grinding, magnetically separating and drying the co-reduction product obtained in the step (3) to obtain ferrosilicon alloy powder and tailings with high alumina content; the method can synchronously realize full-resource high-added-value utilization of the gas ash and the coal gangue on the premise of not adding a carbonaceous reducing agent.)

1. A full resource cooperative utilization method of gas ash and coal gangue is characterized by comprising the following steps:

(1) grinding the gas ash and the coal gangue to powder with more than 200 meshes respectively, adding a certain amount of binder, fully and uniformly mixing according to a certain proportion, and pressing into a cylindrical mixed pressing block;

(2) drying the mixed briquettes prepared in the step (1);

(3) putting the mixed pressing block obtained in the step (2) into a heating furnace, reacting for 90-180 min at the temperature of 1120-1360 ℃, continuously introducing argon into the heating furnace in the heating process, and completing the reaction in an argon atmosphere in the whole reaction process, or maintaining a certain vacuum degree in the heating furnace to complete the reaction in a vacuum environment;

(4) and (4) crushing, grinding, magnetically separating and drying the co-reduction product obtained in the step (3) to obtain ferrosilicon alloy powder and tailings with high alumina content.

2. The method for full-resource synergistic utilization of gas ash and coal gangue as claimed in claim 1, wherein the mass ratio of ingredients of the gas ash to the coal gangue is 4-6: 5.

3. the method for full-resource synergistic utilization of the gas ash and the coal gangue as claimed in claim 1, wherein the binder is polyvinyl alcohol with a mass fraction of 14-16%, and the addition amount is 14-16 wt% of the total mass of the gas ash and the coal gangue.

4. The method for full-resource synergistic utilization of gas ash and coal gangue as claimed in claim 1, wherein the mixed briquettes are dried in an oven at a temperature of 110-130 ℃ for 3-4 h.

5. The method for full-resource cooperative utilization of the gas ash and the coal gangue as claimed in claim 1, wherein if argon is introduced for protection in the whole process, the reduction temperature is 1260-1360 ℃, and the reduction time is 90-120 min; if the vacuum is pumped, the vacuum degree is controlled to be 5-15 Pa, the reduction temperature is 1120-1200 ℃, and the reduction time is 150-180 min.

6. The method for full resource cooperative utilization of the gas ash and the coal gangue as claimed in claim 1, wherein in the step (4), the reduced product is crushed and ground to a particle size of less than 200 meshes which accounts for more than 85% of the total mass of the reduced product, wet magnetic separation is adopted for the magnetic separation, and the magnetic field strength is as follows: 0.08-0.11T.

7. The method for full-resource synergistic utilization of the gas ash and the coal gangue as claimed in claim 1, wherein the silicon content in the powdery ferrosilicon obtained in the step (4) is 18-22%, and the alumina content in the tailings left after magnetic separation is more than 75%.

Technical Field

The invention relates to the technical field of metallurgical solid waste resource utilization, in particular to a full resource cooperative utilization method of gas ash and coal gangue.

Background

Blast furnace gas ash is one of the metallurgical solid wastes generated in the blast furnace smelting process. According to the measurement of about 20kg of blast furnace gas ash generated by smelting each ton of iron, the gas ash amount generated in China every year can reach ten million tons. If the treatment is not proper, the resource is wasted greatly. Meanwhile, the influence on the ecological environment is also serious, and the method is an important problem which each iron and steel enterprise must face.

The coal gangue is solid waste discharged in the coal mining process and the coal washing process, and is a black and gray rock which has lower carbon content and is harder than coal and is associated with a coal bed in the coal forming process. The coal gangue is not used for disposal, occupies a large area of land, and can pollute the atmosphere, farmlands and water bodies. The coal gangue accumulated in China is more than 10 hundred million tons, and 1 hundred million tons of coal gangue are discharged every year.

The gas ash contains ferric oxide as main component and certain amount of silicon dioxide, aluminum oxide and fixed carbon. The coal gangue contains more than 80 percent of silicon dioxide, ferric oxide and aluminum oxide, and contains certain fixed carbon. Found by literature search, Fe₂O₃Can effectively promote SiO₂Reduction of (2), lowering of reaction temperature, and simultaneous separation of Al₂O₃(research on preparation of ferrosilicon alloy by carbothermic reduction of fly ash [ C]// eleventh China annual meeting of steels).

With the increasing of the national environmental protection law enforcement force, the requirement of people on the environmental quality is continuously improved. If the synergistic recycling and high-added-value utilization of various solid wastes can be realized based on the characteristics of the gas ash and coal gangue solid waste resources, not only can the interaction of respective components be fully exerted, but also a carbonaceous reducing agent can not be added in the reduction process, so that the production cost and the energy consumption are greatly reduced, and the method has great significance for realizing green development of social ecology.

Disclosure of Invention

The invention aims to provide a method for full-resource cooperative utilization of gas ash and coal gangue, aiming at the situation, and the method can synchronously realize full-resource high-added-value utilization of the gas ash and the coal gangue on the premise of not adding a carbonaceous reducing agent.

The specific scheme of the invention is as follows: a full resource cooperative utilization method of gas ash and coal gangue specifically comprises the following steps:

(1) grinding the gas ash and the coal gangue to powder with more than 200 meshes respectively, adding a certain amount of binder, fully and uniformly mixing according to a certain proportion, and pressing into a cylindrical mixed pressing block;

(2) drying the mixed briquettes prepared in the step (1);

(3) putting the mixed pressing block obtained in the step (2) into a heating furnace, reacting for 90-180 min at the temperature of 1120-1360 ℃, continuously introducing argon into the heating furnace in the heating process, and completing the reaction in an argon atmosphere in the whole reaction process, or maintaining a certain vacuum degree in the heating furnace to complete the reaction in a vacuum environment;

(4) and (4) crushing, grinding, magnetically separating and drying the co-reduction product obtained in the step (3) to obtain ferrosilicon alloy powder and tailings with high alumina content.

Further, the gas ash and the coal gangue are mixed according to a mass ratio of 4-6: 5.

further, the binder is polyvinyl alcohol with the mass fraction of 14-16%, and the addition amount of the binder is 14-16 wt% of the total mass of the gas ash and the coal gangue.

Further, the mixed pressed block needs to be dried in an oven, the drying temperature is 110-130 ℃, and the drying time is 3-4 hours.

Further, if argon is introduced for protection in the whole process, the reduction temperature is 1260-1360 ℃, and the reduction time is 90-120 min; if the vacuum is pumped, the vacuum degree is controlled to be 5-15 Pa, the reduction temperature is 1120-1200 ℃, and the reduction time is 150-180 min.

Further, in the step (4) of the invention, the reduced product is crushed and ground to a particle size of less than 200 meshes which accounts for more than 85% of the total mass of the reduced product, wet magnetic separation is adopted for the magnetic separation, and the magnetic field strength is as follows: 0.08-0.11T.

Further, in the powdered ferrosilicon alloy obtained in the step (4), the silicon content is 18-22%, and the alumina content in the tailings after magnetic separation is more than 75%.

In the above description, min represents minutes, h represents hours, wt% represents weight percent, Pa represents pressure, and T represents magnetic field strength.

Compared with the prior art, the method for full-resource synergistic utilization of the gas ash and the coal gangue provided by the invention adopts metallurgical solid wastes as main raw materials, simultaneously fully exerts the reducing action of carbon-containing components in the gas ash and the coal gangue, realizes comprehensive high-added-value utilization of various solid wastes without adding a carbonaceous reducing agent, has the advantages of low cost, large solid waste absorption, high comprehensive utilization rate and the like, and has good practical use value and economic value.

Drawings

FIG. 1 is a schematic diagram of the process flow structure of the present invention.

Detailed Description

Referring to fig. 1, the invention is a full resource cooperative utilization method of gas ash and coal gangue, which specifically comprises the following steps:

(1) grinding the gas ash and the coal gangue to powder with more than 200 meshes respectively, adding a certain amount of binder, fully and uniformly mixing according to a certain proportion, and pressing into a cylindrical mixed pressing block;

(2) drying the mixed briquettes prepared in the step (1);

(3) putting the mixed pressing block obtained in the step (2) into a heating furnace, reacting for 90-180 min at the temperature of 1120-1360 ℃, continuously introducing argon into the heating furnace in the heating process, and completing the reaction in an argon atmosphere in the whole reaction process, or maintaining a certain vacuum degree in the heating furnace to complete the reaction in a vacuum environment;

(4) and (4) crushing, grinding, magnetically separating and drying the co-reduction product obtained in the step (3) to obtain ferrosilicon alloy powder and tailings with high alumina content.

Further, in the embodiment, the ratio of the ingredients of the gas ash to the coal gangue by mass is 4-6: 5.

further, in the embodiment, the binder is polyvinyl alcohol with a mass fraction of 14-16%, and the addition amount of the binder is 14-16 wt% of the total mass of the gas ash and the coal gangue.

Further, in the embodiment, the mixed briquettes need to be dried in an oven, the drying temperature is 110-130 ℃, and the drying time is 3-4 hours.

Further, in the embodiment, if argon is introduced for protection in the whole process, the reduction temperature is 1260-1360 ℃, and the reduction time is 90-120 min; if the vacuum is pumped, the vacuum degree is controlled to be 5-15 Pa, the reduction temperature is 1120-1200 ℃, and the reduction time is 150-180 min.

Further, in the step (4) in this embodiment, the reduced product is crushed and ground to a particle size of less than 200 meshes, which accounts for more than 85% of the total mass of the reduced product, wet magnetic separation is adopted for the magnetic separation, and the magnetic field strength is as follows: 0.08-0.11T.

Further, in the powdered ferrosilicon alloy obtained in the step (4) in this embodiment, the content of silicon is 18 to 22%, and the content of alumina in the tailings remaining after magnetic separation is more than 75%.

In the above description, min represents minutes, h represents hours, wt% represents weight percent, Pa represents pressure, and T represents magnetic field strength.

The technical means of the present invention will be described below with reference to specific embodiments.

Example 1:

(1) grinding the gas ash and the coal gangue respectively to form powder with more than 200 meshes. Then adding a binder, fully and uniformly mixing, and pressing into a cylindrical mixed pressing block; wherein, the weight ratio of the ingredients of the gas ash and the coal gangue is 4: 5, the binder is polyvinyl alcohol with the mass fraction of 15%, and the addition amount is 15 wt% of the total mass of the gas ash and the coal gangue.

The main raw material components are as follows: the main mass percent of the gas ash is as follows: SiO 2₂ 8.72%，Al₂O₃ 7.06%，Fe₂O₃56.90%, CaO 3.06%, MgO 0.96%, fixed carbon 27.60%. The main mass percentage of the coal gangue is as follows: SiO 2₂ 52.17%，Al₂O₃25.66%，Fe₂O₃12.10%, MgO 0.64%, fixed carbon 24.70%.

(2) And (2) drying the mixed briquettes in the step (1) at the temperature of 130 ℃ for 3 h, and removing redundant water.

(3) And (3) reducing the mixed briquettes dried in the step (2) at 1280 ℃ for 120 min, and introducing argon for protection in the whole process.

(4) Crushing and grinding the co-reduction product obtained in the step (3) to a particle size of less than 200 meshes which accounts for more than 85% of the total mass of the reduction product, and then carrying out wet magnetic separation to obtain ferrosilicon alloy powder, wherein the magnetic field strength is as follows: 0.10T.

The silicon content of the obtained powdery iron-silicon alloy is 21.26 percent, and meanwhile, the tailings left after magnetic separation contain alumina 75.82 percent.

Example 2:

(1) grinding the gas ash and the coal gangue respectively to form powder with more than 200 meshes. Then adding a binder, fully and uniformly mixing, and pressing into a cylindrical briquette; wherein, the weight ratio of the ingredients of the gas ash and the coal gangue is 6: 5. the adhesive is polyvinyl alcohol with the mass fraction of 16%, and the addition amount of the adhesive is 14 wt% of the total mass of the gas ash and the fly ash.

The main raw material components are as follows: the main mass percent of the gas ash is as follows: SiO 2₂ 8.72%，Al₂O₃ 7.06%，Fe₂O₃56.90%, CaO 3.06%, MgO 0.96%, fixed carbon 27.60%. The main mass percentage of the coal gangue is as follows: SiO 2₂ 52.17%，Al₂O₃25.66%，Fe₂O₃12.10%, MgO 0.64%, fixed carbon 24.70%.

(2) And (2) drying the mixed briquettes in the step (1) at the temperature of 120 ℃ for 3.5 hours, and removing redundant water.

(3) And (3) placing the mixed briquettes dried in the step (2) in a vacuum heating furnace to reduce for 150 min at the temperature of 1200 ℃, and maintaining the vacuum degree of 5-15 Pa in the whole process.

(4) Crushing and grinding the reduced product obtained in the step (3) to a granularity smaller than 200 meshes which accounts for more than 85% of the total mass of the reduced product, and then performing wet magnetic separation to obtain iron-silicon alloy powder, wherein the magnetic field strength is as follows: 0.08T.

The silicon content of the obtained powdery iron-silicon alloy is 20.47 percent. Meanwhile, the tailings left after magnetic separation contain 78.21% of alumina.

Compared with the prior art, the method for full-resource synergistic utilization of the gas ash and the coal gangue provided by the invention adopts metallurgical solid wastes as main raw materials, simultaneously fully exerts the reducing action of carbon-containing components in the gas ash and the coal gangue, realizes comprehensive high-added-value utilization of various solid wastes without adding a carbonaceous reducing agent, has the advantages of low cost, large solid waste absorption, high comprehensive utilization rate and the like, and has good practical use value and economic value.