阅读说明：本技术 一种含单质硫二氧化硅硫酸钙水合物的固废资源化方法 (Solid waste recycling method for calcium sulfate hydrate containing elemental sulfur, silicon dioxide ) 是由 杨鹏 田黎霞 杨皓 宋尉源 于 2021-09-28 设计创作，主要内容包括：一种含单质硫二氧化硅硫酸钙水合物固废的资源化方法,通过磨细碳粉,通入过量氧气循环,加热使硫转化为二氧化硫,碳转化为二氧化碳,混合气转化成三氧化硫同时获得结构疏松的硫酸钙和二氧化硅失水微晶固体。(A method for recycling solid waste containing elemental sulfur, silicon dioxide and calcium sulfate hydrate comprises the steps of grinding carbon powder, introducing excessive oxygen for circulation, heating to convert sulfur into sulfur dioxide, converting carbon into carbon dioxide, converting mixed gas into sulfur trioxide, and simultaneously obtaining calcium sulfate with loose structure and silicon dioxide water-loss microcrystal solid.)

1. A method for recycling solid waste containing elemental sulfur, silicon dioxide and calcium sulfate hydrate is characterized in that the solid waste contains 4-20% of elemental sulfur, 4-20% of silicon dioxide and the balance of calcium sulfate, finely ground carbon powder accounting for 5-10% of the weight of the solid waste is added, the solid waste is sent into a closed container, excess 4-12 times of oxygen (or air or oxygen-enriched air) is introduced for circulation, the mixture is heated to 250-280 ℃ and kept for 20-180 minutes, the elemental sulfur and the oxygen react to generate sulfur dioxide gas, the carbon and the oxygen react to generate carbon dioxide, and the obtained circulation gas contains sulfur dioxide, and the carbon dioxide and the oxygen are sent into the gas to be utilized to synthesize sulfur trioxide; and simultaneously, the water-loss microcrystalline solid of calcium sulfate and silicon dioxide which does not contain elemental sulfur and has a loose structure is obtained, and the microcrystalline solid has better strength than that of anhydrous gypsum after being formed by adding water.

Technical Field

The invention relates to the fields of chemical industry, energy conservation and environmental protection, and discloses a resource method of sulfur-containing solid waste.

Background

The desulfurization of flue gas and coal gas is a common procedure for cleaning gas in the chemical industry, and the dry desulfurization has the advantages of small pollution, low energy consumption and the like, and is widely applied. The desulfurizer is a mixture of oxides containing iron, calcium, aluminum, silicon and the like, the desulfurizer belongs to non-hazardous chemicals and has no pollution hazard to human bodies and the environment, and the waste desulfurizer is hazardous waste due to the absorption and the aggregation of elemental sulfur.

The removed sulfides are usually H2S, SO2, COS, etc., wherein H2S is the main component, and the Fe system desulfurizing agent and the Mn system desulfurizing agent exist in the form of FeS and MnS after H2S is removed. The solid waste is treated by acid washing to generate H2S and SO2, elemental sulfur accumulated on the surface of the desulfurizer and blocking a pore channel is exposed, SiO2 in the framework of the desulfurizer is separated out, and part of CaSO4 is generated at the same time, SO that new solid waste of a mixture of elemental S, SiO2 and CaSO4 is formed.

The dissolving capacity of CS2 for S is adopted for extraction, the application cannot be realized due to the low boiling point of CS2, the performances of other solvents are not good due to the reasons of insufficient dissolving capacity and the like, and the pickling technology of the waste desulfurizing agent is not popularized and applied in a large scale at present due to the reasons. Therefore, a new method is found, which is nontoxic and environment-friendly, separates sulfur from solid waste, realizes waste digestion, produces other products as byproducts, can avoid the problem of new environmental pollution, and can obtain higher economic value.

CN111607704A lili et al announced a treatment process of waste desulfurizer, which mixes the waste desulfurizer with pyrolusite to obtain mixed solid, and leaches the mixed solid with sulfuric acid to obtain leachate; and filtering after carbonization and crystallization to obtain the manganese carbonate. The technology only recovers manganese in the waste slag, neglects the rest of the new hazardous waste of the mixture of sulfur, silicon dioxide and calcium sulfate, and does not treat the waste slag, so that the environmental protection and the economic efficiency of the technology cannot be embodied.

Disclosure of Invention

The invention relates to a method for recycling solid wastes containing elemental sulfur, silicon dioxide and calcium sulfate hydrate, which is characterized by comprising the following steps: the solid waste contains 4-20% of elemental sulfur, 4-20% of silicon dioxide and the balance of calcium sulfate. Feeding the carbon powder and the carbon powder into a closed reactor at a ratio of 0.05-0.1: 1, introducing 4-12 times excess oxygen (or air or oxygen-enriched air) for circulation, and keeping the mixture at 250-280 ℃ for 20-180 minutes. Elemental sulfur is converted into sulfur dioxide, carbon is converted into carbon dioxide, mixed gas containing the sulfur dioxide, the carbon dioxide and oxygen is obtained and sent to a sulfur trioxide synthesis process, and silicon dioxide and calcium sulfate water loss microcrystal solid which does not contain the elemental sulfur and has a loose structure is obtained.

Compared with the prior art, the invention has the advantages that:

(1) the invention provides a method for recycling solid waste containing elemental sulfur, silicon dioxide and calcium sulfate hydrate, wherein the solid acid-washing waste desulfurizer becomes a feasible disposal method, and the waste-free full utilization is realized;

(2) the invention provides a method for recycling solid waste containing elemental sulfur, silicon dioxide and calcium sulfate hydrate, wherein the microcrystalline solid has better strength than anhydrous gypsum after being formed by adding water, and can be directly sold as a product, so that the solid waste is recycled;

(3) the invention provides a method for recycling solid waste containing elemental sulfur, silicon dioxide and calcium sulfate hydrate, wherein S is oxidized into SO₂Then converted into SO₃And the sulfuric acid can be prepared and repeatedly used in the pickling section.

Detailed Description

Example 1: a calcium sulfate hydrate solid waste containing elemental sulfur, silicon dioxide and calcium sulfate, wherein the solid waste contains 10% of elemental sulfur, 16% of silicon dioxide and the balance calcium sulfate, carbon powder which is 10% of the weight of the solid waste and is ground is added, the solid waste is sent into a closed container, 8 times of excessive oxygen (or air or oxygen-enriched air) is introduced for circulation, the solid waste is heated to 250 ℃ and is kept for 160 minutes, elemental sulfur and oxygen react to generate sulfur dioxide gas, the carbon and the oxygen react to generate carbon dioxide, and the obtained circulation gas contains sulfur dioxide, and the carbon dioxide and the oxygen are sent into the gas to be synthesized into sulfur trioxide by utilizing the working procedure; and simultaneously, the water-loss microcrystalline solid of calcium sulfate and silicon dioxide which does not contain elemental sulfur and has a loose structure is obtained, and the microcrystalline solid has better strength than that of anhydrous gypsum after being formed by adding water.

Example 2: solid waste containing elemental sulfur, silicon dioxide and calcium sulfate hydrate, wherein the solid waste contains 8% of elemental sulfur, 14% of silicon dioxide and the balance calcium sulfate, carbon powder which is 7% of the weight of the solid waste and is ground is added, the solid waste is sent into a closed container, excess 6 times of oxygen (or air or oxygen-enriched air) is introduced for circulation, the solid waste is heated to 260 ℃ and is kept for 120 minutes, elemental sulfur and the oxygen react to generate sulfur dioxide gas, the carbon and the oxygen react to generate carbon dioxide, and the obtained circulating gas contains sulfur dioxide, and the carbon dioxide and the oxygen are sent into the gas to be synthesized into sulfur trioxide by utilizing the working procedure; and simultaneously, the water-loss microcrystalline solid of calcium sulfate and silicon dioxide which does not contain elemental sulfur and has a loose structure is obtained, and the microcrystalline solid has better strength than that of anhydrous gypsum after being formed by adding water.

Example 3: solid waste containing elemental sulfur, silicon dioxide and calcium sulfate hydrate is prepared by adding carbon powder which is 5% of the weight of the solid waste and is ground, sending the solid waste into a closed container, introducing excess 4 times of oxygen (or air or oxygen-enriched air) for circulation, heating to 280 ℃ for 90 minutes, reacting elemental sulfur with oxygen to generate sulfur dioxide gas, reacting carbon with oxygen to generate carbon dioxide, and sending the obtained circulating gas containing sulfur dioxide, carbon dioxide and oxygen into a gas utilization process to synthesize sulfur trioxide; and simultaneously, the water-loss microcrystalline solid of calcium sulfate and silicon dioxide which does not contain elemental sulfur and has a loose structure is obtained, and the microcrystalline solid has better strength than that of anhydrous gypsum after being formed by adding water.