Method for removing sulfur in coal gangue through ozone oxidation

Abstract

The invention relates to the technical field of resources and environments, in particular to a method for removing sulfur in coal gangue through ozone oxidation. The method for removing the sulfur in the coal gangue through ozone oxidation comprises the following steps that 1, the coal gangue is crushed and sieved, and coal gangue powder is obtained; 2, adding the coal gangue powder into water, and uniformly mixing to obtain a mixed material; 3, ozone mixed gas is introduced into the mixed material for oxidation, then filtering is conducted, and desulfurized coal gangue powder is obtained. The invention provides a method for removing sulfur in coal gangue by ozone oxidation. The method has the advantages of low cost and short time. By adopting the desulfurization process disclosed by the invention, the sulfur content in the coal gangue can be effectively reduced through simple one-time treatment.

Description

Technical Field

[0001] The invention relates to the field of resource and environmental technology, and in particular to a method for removing sulfur from coal gangue by utilizing ozone oxidation. Background Art

[0002] At present, the methods for removing sulfur from coal gangue mainly include physical methods, chemical methods and microbial methods. Physical methods: mainly through physical coal preparation technology, such as jigging coal preparation, heavy medium coal preparation, chute coal preparation, shaking coal preparation, wind coal preparation, etc., to effectively remove inorganic sulfur (pyrite sulfur) from coal; this method is suitable for removing pyrite sulfur from coal, but the removal effect on organic sulfur is limited. Chemical methods: including alkaline treatment, oxidation method and solvent extraction; these methods can effectively desulfurize in the laboratory, but may face cost and technical difficulties in industrial applications. Microbial methods: using specific microorganisms, such as Thiobacillus, to remove sulfur from coal through chemical reactions in its metabolic process; this method is green and environmentally friendly, but there may be problems such as low desulfurization efficiency and long cycle.

[0003] Therefore, providing a method for effectively removing sulfur from coal gangue with a simple process is what those skilled in the art have been working on. Summary of the invention

[0004] Based on the above content, the present invention provides a method for removing sulfur from coal gangue by using ozone oxidation.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] The present invention provides a method for removing sulfur from coal gangue by using ozone oxidation, the steps of which are as follows:

[0007] Step 1, crushing and screening the coal gangue to obtain coal gangue powder;

[0008] Step 2, adding the coal gangue powder into water and mixing well to obtain a mixed material;

[0009] Step 3, introducing ozone mixed gas into the mixed material for oxidation, and then filtering to obtain desulfurized coal gangue powder.

[0010] In a preferred embodiment of the present invention, in step 1, the screening is specifically through a 3 mm sieve.

[0011] In a preferred embodiment of the present invention, the liquid-to-material ratio of the water to the coal gangue powder is 4:1 to 10:1.

[0012] In a preferred embodiment of the present invention, the ozone mixed gas is a mixed gas of ozone and air; the volume concentration of ozone in the ozone mixed gas is 70% to 90%.

[0013] In a preferred embodiment of the present invention, the oxidation time is 2h to 8h.

[0014] In the present invention, the lower the liquid-to-solid ratio, the longer the oxidation time is required to achieve the same desulfurization effect; a too high liquid-to-solid ratio will increase the water consumption, increase the water treatment cost, and is not conducive to large-scale utilization; the amount of ozone introduced is proportional to the desulfurization efficiency, but if the amount of ozone introduced is too large, it will cause the ozone to stay in the mixed material for too long, and the ozone utilization rate will be low.

[0015] The present invention also provides a method for improving the desulfurization rate in coal gangue, which adopts the above-mentioned method of removing sulfur from coal gangue by utilizing ozone oxidation.

[0016] The present invention discloses the following technical effects:

[0017] The present invention provides a method for removing sulfur from coal gangue by using ozone oxidation, which has the advantages of low cost and short time. By adopting the desulfurization process of the present invention, within a certain liquid-solid ratio range, a simple one-time treatment can effectively reduce the sulfur content in coal gangue. DETAILED DESCRIPTION

[0018] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0019] It should be understood that the terms described in the present invention are only for describing a particular embodiment and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0020] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0021] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to the skilled artisan. The present invention description and examples are exemplary only.

[0022] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0023] The embodiment of the present invention provides a method for removing sulfur from coal gangue by using ozone oxidation, the steps are as follows:

[0024] Step 1, mechanically crushing and screening the blocky coal gangue to obtain coal gangue powder;

[0025] Step 2, using clean water as the liquid phase, adding the coal gangue powder into the clean water and mixing well to obtain a mixed material;

[0026] Step 3, introducing ozone mixed gas into the mixed material to oxidize and dissolve the sulfur in the coal gangue and transfer it to the liquid phase for removal.

[0027] Mechanical crushing: the gangue is broken into large particles and then crushed by a crusher;

[0028] The present invention uses ozone as an oxidant, passes a certain concentration of ozone mixed gas into the mixed material through a gas distributor, and removes sulfur in the coal gangue by oxidizing it to form sulfate ions that enter the liquid phase.

[0029] In the present invention, the sulfur in the coal gangue serves as a medium for the oxidation reaction.

[0030] The filtrate obtained after oxidation filtration is recycled after acid-base neutralization to remove impurities.

[0031] The technical solutions described in the present invention, unless otherwise specified, are all conventional solutions in the art, and the reagents or raw materials used, unless otherwise specified, are purchased from commercial channels or have been disclosed.

[0032] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0033] Example 1: Coal gangue from a certain region (total sulfur content is 2.72%)

[0034] The gangue is mechanically crushed by a pulverizer so that it can all pass through a 3mm sieve to obtain gangue powder; then, the gangue powder is added to water at a liquid-solid ratio of 8:1 (mL / g) and mixed evenly to prepare a mixed material, and 270g of the mixed material is filled into a glass instrument with a gas distributor; a mixed gas of ozone and air with a volume concentration of 70% is continuously introduced into the glass instrument through the gas distributor, and the flow rate of the mixed gas in this embodiment is 2L / min, and the continuous introduction time of the ozone mixed gas is 5h; finally, the desulfurized gangue powder is obtained by filtration. The total sulfur content of the desulfurized gangue powder is 1.7%, and the desulfurization rate reaches 37.5%.

[0035] It has been verified that both inorganic sulfur and organic sulfur in coal gangue are removed.

[0036] Example 2: Coal gangue from a certain area (total sulfur content is 1.59%)

[0037] The gangue is mechanically crushed by a pulverizer so that it can all pass through a 3mm sieve to obtain gangue powder; then, the gangue powder is added to water at a liquid-solid ratio of 10:1 and mixed evenly to prepare a mixed material, and 330g of the mixed material is filled into a glass instrument with a gas distributor; a mixed gas of ozone with a volume concentration of 80% and air is continuously introduced into the glass instrument through the gas distributor, the flow rate of the mixed gas is 2L / min, and the ozone mixed gas is continuously introduced for 6 hours; finally, the desulfurized gangue powder is obtained by filtration. The total sulfur content of the desulfurized gangue powder is 0.78%, and the desulfurization rate reaches 50.9%.

[0038] It has been verified that both inorganic sulfur and organic sulfur in coal gangue are removed.

[0039] Example 3: Coal gangue in a certain area (total sulfur content is 2.8%)

[0040] The gangue is mechanically crushed by a pulverizer so that it can all pass through a 200-mesh screen to obtain gangue powder; then, the gangue powder is added to water at a liquid-solid ratio of 8:1 and mixed evenly to prepare a mixed material, and 270g of the mixed material is filled into a glass instrument with a gas distributor; a mixed gas of ozone and air with a volume concentration of 90% is continuously introduced into the glass instrument through the gas distributor, the flow rate of the mixed gas is 2L / min, and the ozone mixed gas is continuously introduced for 5 hours; finally, the desulfurized gangue powder is obtained by filtration. The total sulfur content of the desulfurized gangue powder is 1.15%, and the desulfurization rate reaches 58.9%.

[0041] It has been verified that both inorganic sulfur and organic sulfur in coal gangue are removed.

[0042] Comparative Example 1: Coal gangue from a certain area (total sulfur content is 9.0%)

[0043] The gangue was mechanically crushed by a pulverizer so that it could all pass through a 200-mesh screen to obtain gangue powder; then, the gangue powder was added to clean water at a liquid-solid ratio of 4:1 to prepare 150g of a mixed material, and hydrogen peroxide accounting for 1% of the volume of the clean water was added to the mixed material, mixed evenly, and stirred for 5 hours; finally, desulfurized gangue powder was obtained by filtration. The total sulfur content of the desulfurized gangue powder was 8.62%, and the desulfurization rate reached 4.2%.

[0044] On the basis of Comparative Example 1, the present invention also verifies the cases where the addition amount of hydrogen peroxide is 5% and 10% (that is, only the addition amount of hydrogen peroxide is adjusted, and the other steps and parameters are the same as those in Comparative Example 1; wherein the case where the addition amount of hydrogen peroxide is 10% is subjected to heating treatment during the stirring process), and the results show that the desulfurization effects are not good, and the desulfurization rates are 2% and 7%, respectively.

[0045] By comparing the embodiments and comparative examples, it can be seen that the effect of removing sulfur from coal gangue by hydrogen peroxide in comparative example 1 is not good. This may be because the simple oxidation performance cannot effectively remove the sulfur from coal gangue. For the removal of sulfur from coal gangue by ozone, in addition to utilizing the oxidation performance of ozone, there may be other unknown mechanisms, which need further study.

[0046] The embodiments described above are only descriptions of the preferred embodiments of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for removing sulfur from coal gangue by using ozone oxidation, characterized in that: Here are the steps: Step 1, crushing and screening the coal gangue to obtain coal gangue powder; Step 2, adding the coal gangue powder into water and mixing well to obtain a mixed material; Step 3, introducing ozone mixed gas into the mixed material for oxidation, and then filtering to obtain desulfurized coal gangue powder.

2. The method for removing sulfur from coal gangue by using ozone oxidation according to claim 1, characterized in that: In step 1, the screening is specifically through a 3 mm sieve.

3. The method for removing sulfur from coal gangue by using ozone oxidation according to claim 1, characterized in that: The liquid-to-material ratio of the water to the coal gangue powder is 4:1 to 10:

1.

4. The method for removing sulfur from coal gangue by using ozone oxidation according to claim 1, characterized in that: The ozone mixed gas is a mixed gas of ozone and air; the volume concentration of ozone in the ozone mixed gas is 70% to 90%.

5. The method for removing sulfur from coal gangue by using ozone oxidation according to claim 1, characterized in that: The oxidation time is 2h to 8h.

6. A method for improving the desulfurization rate in coal gangue, characterized in that: A method for removing sulfur from coal gangue by using ozone oxidation as described in any one of claims 1 to 4.