CN-121975561-A - Desulfurization and deashing method for high-sulfur high-ash coal

CN121975561ACN 121975561 ACN121975561 ACN 121975561ACN-121975561-A

Abstract

The invention belongs to the technical field of high-sulfur high-ash coal utilization, and particularly relates to a desulfurization and deashing method of high-sulfur high-ash coal, which is characterized in that the high-sulfur high-ash coal is subjected to physical coal preparation to obtain low-sulfur low-ash coal with the particle size of <0.5mm, the low-sulfur low-ash coal with the particle size of <0.5mm is subjected to photocatalytic oxidation to obtain extra-low-sulfur low-ash coal, the low-sulfur low-ash coal with the particle size of <0.5mm is prepared into ore pulp with the concentration of 4% -12%, the ore pulp is firstly placed into a reactor with the ultraviolet wave band of 200-300 nm at normal temperature and normal pressure, the photocatalytic reaction is carried out by a modified TiO 2 photocatalyst, the reactor is continuously stirred for 6-12 hours at the speed of 800-1500 rpm, and then the extra-low-sulfur low-ash coal with the concentration of 5% -50% H 2 O 2 , the concentration of 0.01 mol/LKHSO 5 , the concentration of 0.2-1.0 mol/LFe 4 [Fe(CN) 6 ] 3 or the concentration of 50-1000 mg/LO 3 oxidant is added, and the extra-low-sulfur low-ash coal with the sulfur content of 0.3% -8% or less than or equal to normal temperature and less than 6 hours is obtained after the normal temperature and normal pressure. The synergistic effect of ultraviolet, photocatalyst and oxidation realizes that the sulfur content of the ultralow-sulfur low-ash coal obtained by adopting a flotation method is less than or equal to 0.3 percent, the ash content is less than or equal to 8.0 percent, and the sulfur content of the ultralow-sulfur low-ash coal obtained by not adopting the flotation method is less than or equal to 0.5 percent and the ash content is less than or equal to 10.0 percent.

Inventors

Cheng gan
GAO PENGHAO
YAN KEZHOU
FAN BIAO
DENG XIAOWEI
CAO JIAHE
LIU CHANGSHENG

Assignees

山西大学
山西省黄河实验室

Dates

Publication Date: 20260505
Application Date: 20260205

Claims (10)

1.A desulfurization and deashing method of high-sulfur high-ash coal is characterized in that the high-sulfur high-ash coal is subjected to physical coal preparation to obtain low-sulfur low-ash coal with the particle size of less than 0.5mm, and the low-sulfur low-ash coal with the particle size of less than 0.5mm is subjected to photocatalytic oxidation to obtain ultra-low-sulfur low-ash coal; The photocatalytic oxidation method is characterized in that after low-sulfur low-ash coal with the grain size of less than 0.5mm is prepared into ore pulp with the concentration of 4% -12%, the ore pulp is firstly placed into a reactor which is subjected to photocatalysis by a modified TiO 2 photocatalyst under the normal temperature and normal pressure, the reactor is continuously stirred at the speed of 800-1500 rpm for 6-12 hours, then 5% -50% of H 2 O 2 , 0.01 mol/L-0.20 mol/LKHSO 5 and 0.2-1.0 mol/LFe 4 [Fe(CN) 6 ] 3 or 50-1000 mg/LO 3 oxidant are added or mixed, and the extra-low-sulfur low-ash coal with the sulfur content of less than or equal to 0.3% and the ash content of less than or equal to 8.0% is obtained after the reaction is carried out for 3-6 hours again under the normal temperature and normal pressure.
2. The desulfurization and deashing method of high-sulfur high-ash coal according to claim 1 is characterized by comprising the steps of crushing high-sulfur high-ash coal to a grain size of <50mm, and separating the high-sulfur high-ash coal with the grain size of <50mm by adopting a gravity separation device to obtain 1# low-sulfur low-ash coal and 1# high-sulfur high-ash coal respectively; The 1# low-sulfur low-ash coal is screened by 13mm to obtain 13-50 mm-sized 2# low-sulfur low-ash coal and <13 mm-sized 3# low-sulfur low-ash coal; Crushing the No. 1 high-sulfur high-ash coal to be less than 13mm, and then adopting gravity separation to obtain No. 4 low-sulfur low-ash coal and No.2 high-sulfur high-ash coal respectively; Mixing the 4# low-sulfur low-ash coal and the 3# low-sulfur low-ash coal, and screening the mixture by 3mm to obtain the 3-13 mm-sized 5# low-sulfur low-ash coal and the <3 mm-sized 6# low-sulfur low-ash coal respectively; And (3) classifying the No. 6 low-sulfur low-ash coal by 0.5mm to obtain No. 7 low-sulfur low-ash coal with the particle size of 0.5-3 mm and No. 8 low-sulfur low-ash coal with the particle size of less than 0.5mm respectively.
3. The desulfurization and deashing method of high-sulfur high-ash coal according to claim 2 is characterized in that 2# high-sulfur high-ash coal is crushed to be less than 3mm, 0.5-3 mm coarse-grain coal and <0.5mm fine-grain coal are respectively obtained through grading of 0.5mm grain size, coarse-grain high-sulfur coal and coarse-grain high-ash coal are respectively obtained from the 0.5-3 mm coarse-grain coal through gravity separation, fine-grain high-sulfur coal and fine-grain high-ash coal are respectively obtained from the <0.5mm fine-grain coal through centrifugal separation, sulfur content in the coarse-grain high-sulfur coal and the fine-grain high-sulfur coal is greater than or equal to 25% and used for sulfuric acid production, and the coarse-grain high-ash coal and the fine-grain high-ash coal are used as building materials according to XRD components.
4. The desulfurization and deashing method of high-sulfur high-ash coal according to claim 2 is characterized in that 3# high-sulfur high-ash coal with 3mm size and 4# high-sulfur high-ash coal with <3mm size are obtained by screening 2# high-sulfur high-ash coal with 3mm size and 3# high-sulfur high-ash coal with <3mm size respectively, and 5# high-sulfur high-ash coal with 0.5mm size and 6# high-sulfur high-ash coal with 0.5mm size are obtained by grading 4# high-sulfur high-ash coal with 0.5mm size and 3mm size respectively; the sulfur content in the 1-8 # low-sulfur low-ash coal is less than or equal to 1.0%, the ash content is less than or equal to 10.0%, the sulfur content in the 1-5 # high-sulfur high-ash coal is more than or equal to 15.0%, and the ash content is more than or equal to 90.0%.
5. The desulfurization and deashing method of high-sulfur high-ash coal according to claim 1 is characterized by comprising the steps of crushing high-sulfur high-ash coal to a grain size of <50mm, and separating the high-sulfur high-ash coal with the grain size of <50mm by adopting a gravity separation device to obtain 1# low-sulfur low-ash coal and 1# high-sulfur high-ash coal respectively; Crushing the No. 1 high-sulfur high-ash coal to be less than 3mm, then adopting gravity separation to respectively obtain No. 2 low-sulfur low-ash coal and No. 2 high-sulfur high-ash coal, mixing the No. 2 low-sulfur low-ash coal and the No. 1 low-sulfur low-ash coal, grinding to be less than 0.5mm size fraction, and then adopting a flotation method to respectively obtain No. 3 low-sulfur low-ash coal and No. 4 low-sulfur low-ash coal with the size fraction less than 0.5 mm.
6. The desulfurization and deashing method of high-sulfur high-ash coal according to claim 1 is characterized by comprising the steps of crushing high-sulfur high-ash coal to a grain size of <50mm and a grain size of <3mm in sequence, grinding the crushed high-sulfur high-ash coal to a grain size of <0.50mm, and respectively obtaining 1# low-sulfur low-ash coal with sulfur content less than or equal to 1.0% and ash content less than or equal to 10.0% and 1# high-sulfur high-ash coal with sulfur content more than or equal to 15.0% and ash content more than or equal to 90.0% by adopting a flotation method, wherein the grain size of 1# low-sulfur low-ash coal is <0.5mm.
7. The desulfurization and deashing method of high-sulfur high-ash coal according to claim 5 or 6, wherein the concentration of the flotation feed pulp is 40-80 g/L, the consumption of the collector is 100-800 g/t, and the consumption of the foaming agent is 40-200 g/t; The collecting agent is kerosene, diethyl phthalate, n-dodecane or diesel oil, the foaming agent is octanol or No. 2 oil, the sulfur-containing mineral inhibitor is sodium lignin sulfonate, calcium lignin sulfonate, pyrogallol, calcium oxide or calcium hypochlorite, the dosage range is 600-5000 g/t, and the flotation time is 1-5 min.
8. The desulfurization and deashing method of high-sulfur high-ash coal according to claim 2 or 5, wherein the heavy-duty separator with the grain size of <50mm is a jigging separator, a spiral separator or a heavy-medium shallow-trough separator, and the heavy-duty separator with the grain size of <3mm is a heavy-medium cyclone.
9. The desulfurization and deashing method of high-sulfur high-ash coal according to any one of claims 1 to 6, wherein the reactor comprises a reactor body (1) and a stirring assembly (2), the stirring assembly (2) is arranged in the reactor body (1), a driving motor (3) connected with the stirring assembly (2) is arranged on the reactor body (1), the stirring assembly (2) is driven to rotate through the driving motor (3), and an auxiliary ultraviolet lamp assembly (4) is arranged at the inner top of the reactor body (1).
10. The desulfurization and deashing method of high-sulfur high-ash coal according to claim 9, wherein the inner wall of the reactor body (1) is provided with a spiral guide plate or a spiral guide groove, the upper part of the reactor body (1) is communicated with a discharge pipe (46), and the lower part of the reactor body (1) is communicated with a feed pipe (45); the stirring assembly (2) comprises a stirring shaft and stirring blades (21), wherein the stirring shaft consists of at least two supporting shafts (20) which are coaxially and rotatably connected, and each supporting shaft (20) is provided with the stirring blade (21) and different in height, each supporting shaft (20) is correspondingly connected with a driving motor (3), and the supporting shafts (20) and the output shafts of the driving motors (3) are in gear transmission; The auxiliary ultraviolet lamp assembly (4) comprises three auxiliary ultraviolet lamps (40) and connecting seats (41), wherein the three auxiliary ultraviolet lamps (40) are rotatably connected with the reactor body (1), the three auxiliary ultraviolet lamps (40) are fixedly connected with the connecting seats (41), a gear ring (43) is fixedly connected to the connecting seats (42), a driving shaft (42) is rotatably connected to the reactor body (1), and transmission gears (44) meshed with the gears and the gear ring (43) are respectively arranged at two ends of the driving shaft (42).

Description

Desulfurization and deashing method for high-sulfur high-ash coal Technical Field The invention belongs to the technical field of high-sulfur high-ash coal utilization, and particularly relates to a desulfurization and deashing method of high-sulfur high-ash coal. Background Coal is one of the most abundant, most widely distributed and most economical energy sources in the world, and at the end of 2024, the worldwide coal has ascertained reserves of 1.074 trillion tons. In 2024, the total energy consumption of China is 59.6 hundred million tons of standard coal, the coal consumption is 53.2% of the total energy consumption, and the raw coal yield is 47.8 hundred million tons and is increased by 1.2% in the same ratio. With the development of high quality of industry, the quality requirement on coal is higher and higher, and part of coal resources are difficult to utilize due to high sulfur and high ash, so that the supply of high-quality coal resources is tense. In coal coking production, about 60% of sulfur remains in the coke, and limestone is required to be added to neutralize the sulfur and convert it into slag for removal, which affects the blast furnace yield and smelting strength. In blast furnace iron making, about 80% of sulfur in the coke is transferred to pig iron, which causes hot shortness and is unusable. In the actual production of iron making, the sulfur content in the coke is increased by 0.1%, the coke ratio is increased by 1.5%, and the pig iron yield is reduced by 2% -2.5%. A large amount of pyrite in coal not only promotes spontaneous combustion of the coal, but also causes ineffective transportation, increasing transportation costs. The method for removing sulfur in the high-sulfur coking coal has important practical significance for expanding the range of coking coal resources, reasonably utilizing the coking coal, reducing the coal blending cost and increasing the enterprise benefit. At present, physical washing and selecting technologies such as jigging, heavy medium sorting and the like are commonly adopted in the industry aiming at clean utilization of high-sulfur high-ash coal. The method has good removal effect on pyrite sulfur and part of external ash existing in a mineral form, but has obvious limitations that firstly, the traditional physical method has extremely limited removal capability on organic sulfur tightly combined with coal organic matters in a molecular form, and deep desulfurization is difficult to realize, and secondly, the prior art aims at producing single qualified electric coal, and has low resource utilization rate. The market has increasingly stringent requirements for ultra-low sulfur and ultra-low ash high-quality clean coal, for example, the clean coal is used as a chemical raw material, a blast furnace injection fuel or a high-end civil fuel, and the index of the clean coal often requires the sulfur content to be lower than 0.5% or even 0.3%, and the ash content to be lower than 10.0% or 8.0%. The conventional technology route is difficult to obtain the high-quality clean coal product directly from the high-sulfur high-ash raw coal stably and economically, and the comprehensive benefit of recycling and product diversification is realized. Disclosure of Invention Aiming at the technical problems, the invention provides a desulfurization and deashing method of high-sulfur high-ash coal, which is used for obtaining various products in the physical coal preparation process and obtaining the ultralow-sulfur low-ash coal through a photocatalytic oxidation method. In order to solve the technical problems, the invention adopts the following technical scheme: The desulfurizing and deashing process of high sulfur and high ash coal includes physical separation to obtain low sulfur and low ash coal of 0.5mm size and photocatalytic oxidation to obtain low sulfur and low ash coal of 0.5mm size; The photocatalytic oxidation method is characterized in that after low-sulfur low-ash coal with the grain size of less than 0.5mm is prepared into ore pulp with the concentration of 4% -12%, the ore pulp is firstly placed into a reactor which is subjected to photocatalysis by a modified TiO 2 photocatalyst under the normal temperature and normal pressure, the reactor is continuously stirred at the speed of 800-1500 rpm for 6-12 hours, then 5% -50% of H 2O2, 0.01 mol/L-0.20 mol/LKHSO 5 and 0.2-1.0 mol/LFe 4[Fe(CN)6]3 or 50-1000 mg/LO 3 oxidant are added or mixed, and the extra-low-sulfur low-ash coal with the sulfur content of less than or equal to 0.3% and the ash content of less than or equal to 8.0% is obtained after the reaction is carried out for 3-6 hours again under the normal temperature and normal pressure. Crushing the high-sulfur high-ash coal to a grain size of less than 50mm, and separating the high-sulfur high-ash coal with the grain size of less than 50mm by adopting a gravity separation device to respectively obtain No.1 low-sulfur low-ash coal and No.1 high-sul