阅读说明：本技术 一种废弃菌棒焙烧赤泥的资源化循环处理工艺 (recycling treatment process for red mud roasted by waste mushroom sticks ) 是由 田森林 杨皓 宁平 张秋林 钟俊波 于 2019-09-17 设计创作，主要内容包括：本发明公开了一种废弃菌棒焙烧赤泥的资源化循环处理工艺,包括煅烧、焙烧与吸附、浸出、一次结晶、二次结晶及脱盐步骤。本发明可有效将废弃菌棒以及赤泥资源化,并且部分产物又能够返回其他步骤,形成循环处理,在保障工艺正常进行的同时具有节约资源的优点；本发明工艺有效减少固体废弃物排放、降低资源消耗。(The invention discloses a resource recycling treatment process of waste mushroom-stick roasted red mud, which comprises the steps of calcining, roasting and adsorbing, leaching, primary crystallizing, secondary crystallizing and desalting. The method can effectively recycle the waste mushroom sticks and the red mud, and partial products can return to other steps to form circular treatment, so that the method has the advantage of saving resources while ensuring the normal operation of the process; the process effectively reduces the discharge of solid wastes and reduces the resource consumption.)

1. a resource recycling treatment process for red mud roasted by waste mushroom sticks is characterized by comprising the following steps:

s1, calcining: crushing the waste mushroom sticks, and then feeding the crushed mushroom sticks into a calcining furnace for calcining to obtain a calcined slag material;

s2, roasting and adsorbing: uniformly mixing the calcined slag material and the red mud for roasting, which adsorbs organic matters and carbon dust in roasting smoke, according to the mass ratio of 1: 0.3-2, feeding the mixture into a roasting furnace for roasting, and feeding oxygen-enriched air during roasting to obtain dry materials; flue gas generated during roasting is subjected to heat recovery firstly and then is adsorbed by fresh red mud to obtain red mud for roasting and purified flue gas;

s3, leaching: recovering heat of the dry material obtained in the step S2, sending the dry material into a leaching device containing pure water, and performing solid-liquid separation to obtain a solution for leaching soluble components and dealkalized slag;

s4, primary crystallization: feeding the solution obtained in the step S3 into a first crystallizer, introducing gas into the first crystallizer at the same time, separating out calcium carbonate crystals, then carrying out solid-liquid separation, combining the solids with the dealkalized slag obtained in the step S3, and discharging the gas in the first crystallizer;

s5, secondary crystallization: sending the liquid obtained after the solid-liquid separation in the step S4 into a second crystallizer, sending the purified flue gas obtained in the step S2 into the second crystallizer, separating out sodium bicarbonate and potassium bicarbonate crystals, and carrying out solid-liquid separation on the crystals; the flue gas discharged by the second crystallizer is used as the gas introduced into the first crystallizer;

s6, desalting: pressurizing the residual crystallization liquid obtained after the solid-liquid separation in the step S5, desalting through membrane separation, wherein one part of pure water is used as water for a leaching device in the step S3, the other part of pure water is sent out, and concentrated brine is sent back to a second crystallizer to recover sodium bicarbonate and potassium bicarbonate.

2. the resource recycling treatment process of the red mud roasted by the waste mushroom sticks as claimed in claim 1, wherein the waste mushroom sticks in the step S1 are waste mushroom sticks, waste agaric mushroom sticks or waste oyster mushroom sticks.

3. the recycling treatment process of the red mud roasted by the waste mushroom sticks according to claim 1, wherein the water content of the waste mushroom sticks in the step S1 is 55-60%.

4. the recycling treatment process of the red mud roasted by the waste mushroom sticks as claimed in claim 1, wherein the oxygen-enriched air in the step S2 is air containing 40-70% of oxygen.

5. The recycling treatment process of the red mud roasted by the waste mushroom sticks as recited in claim 1, wherein the roasting temperature in the step of S2 is 470-600 ℃, and the roasting time is 0.1-1 h.

6. the recycling treatment process for the red mud roasted by the waste mushroom sticks according to claim 1, which is characterized in that the pH value of the solid slag of the mixture of the roasted slag material and the red mud for roasting in the step S2 is 6.8-7.1.

7. the recycling treatment process of the red mud roasted by the waste mushroom sticks according to claim 1, wherein the pH of the dealkalized slag in the step S3 is 6.8-7.1.

8. The recycling treatment process of the red mud roasted by the waste mushroom sticks as claimed in claim 1, which is characterized in that the crystal substances generated in the step S5 are sent to a recrystallization process to produce soda ash.

9. the recycling treatment process of the red mud roasted by the waste mushroom sticks as claimed in claim 1, wherein the pressure in the step S6 is increased to 0.3-1.5 MPa.

Technical Field

the invention belongs to the technical field of environmental protection, and particularly relates to a recycling treatment process for red mud roasted by waste mushroom sticks.

Background

the red mud is polluting waste residue discharged when aluminum oxide is extracted in the aluminum industry, and generally 1.0-2.0 tons of red mud are additionally generated when 1 ton of aluminum oxide is produced on average. China, as the 4 th alumina producing country in the world, discharges up to millions of tons of red mud every year. The production of a large amount of red mud has caused direct and indirect influences on the production and life of human beings in many aspects, so the yield and the harm of the red mud are reduced to the maximum extent, and the realization of multi-channel and large-quantity resource utilization is urgent.

CN104843750A is published by Kunming university Jushahua and the like, and a method for converting aluminum in Bayer process red mud from a hydrated garnet phase to an alumina phase is disclosed, wherein step 1, Bayer process red mud is dried and ground into fine powder with the granularity of 80-200 meshes, hydrocarbon organic binder with the mass of 2-8% of the fine powder is added into the fine powder to be uniformly mixed, and round particles with the particle size of 1-5 mm are prepared by manual kneading or a granulator; and 2, roasting the round particles by microwaves for 20-100 min under the conditions that the microwave power is 1.5-3 kW and the microwave roasting temperature is 400-800 ℃, and finally, preserving the heat for 10-60 min under the conditions that the temperature is 400-800 ℃, so that the Bayer process red mud round particles converted from hydrated garnet phases to alumina phases can be obtained.

Li Xiang CN108754134A of Zhongzhu Huatian engineering technology Limited company announces a comprehensive utilization process of red mud, taking red mud and additives to prepare materials, uniformly mixing the materials, pressing the materials into blocks, and obtaining dry blocks at the temperature of 200-350 ℃ with the water content of the dry blocks being 1-5%; and (2) placing the dried agglomerate obtained in the step (1) and a reducing agent into an electric arc furnace for reduction smelting, reducing iron elements in the agglomerate into metallic iron and melting into molten iron, and directly casting the molten iron obtained after slag-iron separation into iron blocks.

the coke and bentonite raw materials are adopted to recycle the red mud as resources, and the coke and bentonite raw materials have too high values, so the method for recycling the red mud effective components is an irrecoverable method.

The waste mushroom sticks are solid wastes generated in the production process of edible mushrooms, because the mushroom sticks have high water content and are difficult to be directly combusted and utilized, the mushroom sticks are stacked for natural fermentation and decay in a common method, and because lignin is difficult to digest, the mushroom sticks can become soil only after decades. The amount of waste fungus sticks in Beijing City in 2010 is 8 million tons, and the amount of waste fungus sticks in China every year is estimated to be more than 300 million tons at present.

The waste mushroom sticks generally contain 20-35% fixed carbon, 10-15% hydrogen, and 50-60% water. The common treatment method is to adopt tail gas after combustion to adsorb and purify, so as to ensure that secondary environmental pollution caused by benzene, heavy hydrocarbon and smoke emission can not be caused in the combustion process of the waste activated carbon.

CN203771423U Hubei Xinguan food science and technology Limited Yangxiu, bulletin, says that the common method for fungus stick combustion is: (1) burning the dried powder on a powder burner; (2) drying and granulating for reuse; (3) adding wood chips or coal and other fuels for mixed combustion; however, these methods have the disadvantages of smoke pollution, large floor area, low efficiency and the like, and the most difficult problem to be solved is the environmental pollution caused by dust and smoke discharge during drying.

therefore, it is necessary to develop a recycling treatment process for waste bacteria rod roasted red mud, which can effectively reduce the emission of solid wastes and reduce the resource consumption.

disclosure of Invention

the invention aims to provide a recycling treatment process for waste mushroom-stick roasted red mud.

the object of the invention is achieved by the following steps:

s1, calcining: crushing the waste mushroom sticks, and then feeding the crushed mushroom sticks into a calcining furnace for calcining to obtain a calcined slag material;

S2, roasting and adsorbing: uniformly mixing the calcined slag material and the red mud for roasting, which adsorbs organic matters and carbon dust in roasting smoke, according to the mass ratio of 1: 0.3-2, feeding the mixture into a roasting furnace for roasting, and feeding oxygen-enriched air during roasting to obtain dry materials, wherein the dry materials are rich in metallic iron, aluminum, sodium carbonate, iron oxide, aluminum oxide, potassium carbonate and calcium silicate; flue gas generated during roasting is subjected to heat recovery firstly and then is adsorbed by fresh red mud to obtain red mud for roasting and purified flue gas;

s3, leaching: recovering heat of the dry material obtained in the step S2, sending the dry material into a leaching device containing pure water, and performing solid-liquid separation to obtain a solution for leaching soluble components and dealkalized slag;

s4, primary crystallization: feeding the solution obtained in the step S3 into a first crystallizer, introducing gas into the first crystallizer at the same time, separating out calcium carbonate crystals, then carrying out solid-liquid separation, combining the solids with the dealkalized slag obtained in the step S3, and discharging the gas in the first crystallizer;

S5, secondary crystallization: sending the liquid obtained after the solid-liquid separation in the step S4 into a second crystallizer, sending the purified flue gas obtained in the step S2 into the second crystallizer, separating out sodium bicarbonate and potassium bicarbonate crystals, and carrying out solid-liquid separation on the crystals; the flue gas discharged by the second crystallizer is used as the gas introduced into the first crystallizer;

s6, desalting: pressurizing the residual crystallization liquid obtained after the solid-liquid separation in the step S5, desalting through membrane separation, wherein one part of pure water is used as water for a leaching device in the step S3, the other part of pure water is sent out, and concentrated brine is sent back to a second crystallizer to recover sodium bicarbonate and potassium bicarbonate.

the invention has the beneficial effects that: according to the invention, the waste mushroom sticks and the red mud are roasted, the smoke generated by roasting is adsorbed and purified by using the fresh red mud, the adsorbed red mud is used as the red mud for roasting, and meanwhile, the heat of dry materials and the smoke is recovered; leaching, primary crystallization, secondary crystallization and desalting of dry materials; the obtained dealkalized slag can meet the soil requirement; the crystal generated by the secondary crystallization can be used for producing sodium carbonate in the recrystallization process; the pure water generated in the desalting step can be used for leaching water and can also be sent out, and the strong brine is returned to the second crystallizer to continuously recover sodium bicarbonate and potassium bicarbonate; the flue gas generated by roasting is adsorbed and purified by the red mud and then is sequentially introduced into the second crystallizer and the first crystallizer, and the gas discharged from the first crystallizer can be directly discharged, so that the environmental pollution is avoided. The waste mushroom sticks and the red mud can be effectively recycled through the treatment of the invention, and part of products can return to other steps to form cycle treatment, thereby having the advantage of saving resources while ensuring the normal operation of the process; the process effectively reduces the discharge of solid wastes and reduces the resource consumption.

drawings

FIG. 1 is a schematic view of the process of the present invention.

Detailed Description

The invention is further described with reference to the accompanying drawings, but the invention is not limited in any way, and any alterations or substitutions based on the teaching of the invention are within the scope of the invention.

the invention as shown in figure 1 comprises the following steps:

S1, calcining: crushing the waste mushroom sticks with the moisture content of 55-60%, and then feeding the crushed mushroom sticks into a calcining furnace for calcining to obtain a calcined slag material;

s2, roasting and adsorbing: uniformly mixing the calcined slag material and the red mud for roasting, which adsorbs organic matters and carbon dust in roasting smoke, according to the mass ratio of 1: 0.3-2, feeding the mixture into a roasting furnace for roasting, and feeding oxygen-enriched air during roasting to obtain dry materials; flue gas generated during roasting is subjected to heat recovery firstly and then is adsorbed by fresh red mud to obtain red mud for roasting and purified flue gas;

S3, leaching: recovering heat of the dry material obtained in the step S2, sending the dry material into a leaching device containing pure water, and performing solid-liquid separation to obtain a solution for leaching soluble components and dealkalized slag;

S4, primary crystallization: feeding the solution obtained in the step S3 into a first crystallizer, introducing gas into the first crystallizer at the same time, separating out calcium carbonate crystals, then carrying out solid-liquid separation, combining the solids with the dealkalized slag obtained in the step S3, and discharging the gas in the first crystallizer;

s5, secondary crystallization: sending the liquid obtained after the solid-liquid separation in the step S4 into a second crystallizer, sending the purified flue gas obtained in the step S2 into the second crystallizer, separating out sodium bicarbonate and potassium bicarbonate crystals, and carrying out solid-liquid separation on the crystals; the flue gas discharged by the second crystallizer is used as the gas introduced into the first crystallizer;

S6, desalting: pressurizing the residual crystallization liquid obtained after the solid-liquid separation in the step S5, desalting through membrane separation, wherein one part of pure water is used as water for a leaching device in the step S3, the other part of pure water is sent out, and concentrated brine is sent back to a second crystallizer to recover sodium bicarbonate and potassium bicarbonate.

preferably, the water content of the waste mushroom sticks in the step S1 is 55-60%.

preferably, the calcination described in step S1 is.

preferably, the oxygen-enriched air in the step S2 is air containing 40-70% of oxygen.

preferably, the roasting temperature in the S2 step is 470-600 ℃, and the roasting time is 0.1-1 h.

Preferably, the solid slag pH of the mixture of the calcined slag charge and the red mud for roasting in the step S2 is 6.8-7.1.

preferably, the pH of the dealkalized residue in the step S3 is 6.8-7.1.

preferably, the crystal substance generated in the step of S5 is sent to a recrystallization process to produce soda ash.

Preferably, the pressurization in the step of S6 is to 0.3 to 1.5 MPa.

the present invention will be further described with reference to examples 1 to 16.