Structural properties of residual carbon in coal gasification fine slag and their influence on flotation separation and resource utilization:A review

Coal gasification fine slag(FS)is a typical solid waste generated in coal gasification.Its current disposal methods of stockpil-ing and landfilling have caused serious soil and ecological hazards.Separation recovery and the high-value utilization of residual carbon(RC)in FS are the keys to realizing the win-win situation of the coal chemical industry in terms of economic and environmental benefits.The structural properties,such as pore,surface functional group,and microcrystalline structures,of RC in FS(FS-RC)not only affect the flotation recovery efficiency of FS-RC but also form the basis for the high-value utilization of FS-RC.In this paper,the characteristics of FS-RC in terms of pore structure,surface functional groups,and microcrystalline structure are sorted out in accordance with gasification type and FS particle size.The reasons for the formation of the special structural properties of FS-RC are analyzed,and their influence on the flotation separation and high-value utilization of FS-RC is summarized.Separation methods based on the pore structural characterist-ics of FS-RC,such as ultrasonic pretreatment-pore-blocking flotation and pore breaking-flocculation flotation,are proposed to be the key development technologies for improving FS-RC recovery in the future.The design of low-cost,low-dose collectors containing polar bonds based on the surface and microcrystalline structures of FS-RC is proposed to be an important breakthrough point for strengthening the flotation efficiency of FS-RC in the future.The high-value utilization of FS should be based on the physicochemical structural proper-ties of FS-RC and should focus on the environmental impact of hazardous elements and the recyclability of chemical waste liquid to es-tablish an environmentally friendly utilization method.This review is of great theoretical importance for the comprehensive understand-ing of the unique structural properties of FS-RC,the breakthrough of the technological bottleneck in the efficient flotation separation of FS,and the expansion of the field of the high value-added utilization of FS-RC.

Effective separation of coal gasification fine slag: Role of classification and ultrasonication in enhancing flotation

Effective separation of residual carbon and ash is the basis for the resource utilization of coal gasification fine slag(CGFS).The conventional flotation process of CGFS has the bottlenecks of low carbon recovery and high collector dosage.In order to address these issues,CGFS sample taken from Shaanxi,China was used as the study object in this paper.A new process of size classification-fine grain ultrasonic pretreatment flotation(SC-FGUF)was proposed and its separation effect was compared with that of wholegrain flotation(WGF)as well as size classification-fine grain flotation(SC-FGF).The mechanism of its enhanced separation effect was revealed through flotation kinetic fitting,flotation flow foam layer stability,particle size composition,surface morphology,pore structure,and surface chemical property analysis.The results showed that compared with WGF,pre-classification could reduce the collector dosage by 84.09%and the combination of pre-classification and ultrasonic pretreatment could increase the combustible recovery by 17.29%and up to 93.46%.The SC-FGUF process allows the ineffective adsorption of coarse residual carbon to collector during flotation stage to be reduced by pre-classification,and the tightly embedded state of fine CGFS particles is disrupted and surface oxidizing functional group occupancy was reduced by ultrasonic pretreatment,thus carbon and ash is easier to be separated in the flotation process.In addition,some of the residual carbon particles were broken down to smaller sizes in the ultrasonic pretreatment,which led to an increase in the stability of flotation flow foam layer and a decrease in the probability of detachment of residual carbon particles from the bubbles.Therefore,SCFGUF could increase the residual carbon recovery and reduce the flotation collector dosage,which is an innovative method for carbon-ash separation of CGFS with good application prospect.

Occurrence,leaching behavior,and detoxification of heavy metal Cr in coal gasification slag

Coal gasification slag(CGS)is a type of solid waste produced during coal gasification,in which heavy metals severely restrict its resource utilization.In this work,the mineral occurrence and distribution of typical heavy metal Cr in CGS is investigated.The leaching behavior of Cr under different conditions is studied in detail.Acid leaching-selective oxidation-coprecipitation method is proposed based on the characteristics of Cr in CGS.The detoxification of Cr in CGS is realized,and the detoxification mechanism is clarified.Results show that Cr is highly enriched in CGS.The speciation of Cr is mainly residual fraction(74.47%-86.12%),which is combined with amorphous aluminosilicate.Cr^(3+)and Cr^(6+)account for 90.93%-94.82%and 5.18%-9.07%of total Cr,respectively.High acid concentration and high liquid-solid ratio are beneficial to destroy the lattice structure of amorphous aluminosilicate,thus improving the leaching efficiency of Cr,which can reach 97.93%under the optimal conditions.Acid leaching-selective oxidation-coprecipitation method can realize the detoxification of Cr in CGS.Under the optimal conditions,the removal rates of Fe^(3+)and Cr^(3+)in the leaching solution are 80.99%-84.79%and 70.58%-71.69%,respectively,while the loss rate of Al^(3+)is only 1.10%-3.35%.Detoxification slag exists in the form of Fe-Cr coprecipitation(Fe_(1-x)Cr_xOOH),which can be used for smelting.The detoxification acid leaching solution can be used to prepare inorganic polymer composite coagulant poly-aluminum chloride(PAC).This study can provide theoretical and data guidance for detoxification of heavy metal Cr in CGS and achieve resource utilization of coal gasification solid waste.

Effect of slag composition on corrosion resistance of high chromia refractory bricks for industrial entrained-flow gasifier

The slag composition corresponding to different coals varies significantly,which directly affects the operation of industrial entrained-flow gasifier and the service life of refractory bricks.In this study,the corrosion resistance of several typical coal slags for gasification on high chromia refractory bricks was comparatively investigated by static laboratory crucible tests and thermodynamic simulations.The results demonstrated that the corrosion degree of high chromia refractory bricks by different coal slags was high-Ca/Na slag>high-Fe slag>high-Si/Al slag.The surface structure of the refractory was relatively flat after corrosion by high-Si/Al slag,and the primary corrosion reaction was the partial dissolution of the matrix by the slag.High-Fe slag was prone to the precipitation of iron phases as well as the formation of(Mg,Fe)(Al,Cr)_(2)O_(4)composite spinel layer at the slag/refractory interface.The high-Ca/Na slag was susceptible to react with the refractory to yield a low melting point phase,which led to the destruction of the matrix structure of the refractory and an isolated distribution of particles.In addition,the monoclinic ZrO_(2) in the refractory reacted with CaO in the slag to formed calcium zirconate,which loosened its phase toughening effect,was the primary factor that aggravated the refractory corrosion.

Review of the characteristics and graded utilisation of coal gasification slag

The characteristics of the energy structure of rich coal,less oil and less gas,coupling with a high external dependence on oil and natural gas and the emphasis on the efficient and clean utilisation of coal,have brought opportunities for coal chemical industry.However,with the large-scale popularisation of coal gasification technology,the production and resulting storage of coal gasification slag continue to increase,which not only result in serious environmental pollution and a waste of terrestrial resources,but also seriously affect the sustainable development of coal chemical enterprises.Hence,the treatment of coal gasification slag is extremely important.In this paper,the production,composition,morphology,particle size structure and water holding characteristics of coal gasification slag are introduced,and the methods of carbon ash separation of gasification slag,both domestically and abroad,are summarised.In addition,the paper also summarises the research progress on gasification slag in building materials,ecological restoration,residual carbon utilisation and other high-value utilisation,and ultimately puts forward the idea of the comprehensive utilisation of gasification slag.For large-scale consumption to solve the environmental problems of enterprises and achieve high-value utilisation to increase the economic benefits of enterprises,it is urgent to zealously design a reasonable and comprehensive utilisation technologies with simple operational processes,strong adaptability and economic benefits.

Preparation of Sialon Powder from Coal Gasification Slag

X-ray fluorescence spectrometry（XRF）,X-ray powder diffractometry（XRD） and scanning electron microscopy（SEM） were used to characterize the chemical composition,phase constituent and microstructure of the coal gasification slag.Sialon powders were synthesized by carbothermal reduction and nitridation using the coal gasification slag as raw materials.The experimental results showed that glass and amorphous carbon were the main phases,quartz and calcite as minor crystalline phases were also presented in porous coal gasification slag.Main constituents of coal gasification slag were SiO2,Al2O3,CaO and residual carbon.Sialon powder with Ca-α-Sialon as main crystalline phase can be synthesized when coal gasification slag powders were reduced and nitrided at 1500 ℃ for 9 h using nitrogen flow of 500 ml/min.The coal gasification slag is a valuable and economic starting material for preparing Sialon powders.

Lowering ash slagging and fouling tendency of high-alkali coal by hydrothermal pretreatment

High-alkali species in coal are notorious for causing ash slagging and fouling incidents.In this paper,four high-alkali coals were individually subject to hydrothermal pretreatment(HTP),within a batch-type autoclave at 300 -C for 1 h,and the treated coals were analyzed,along with the oxygen-containing functional groups determined by Fourier transform infrared spectrometer(FT-IR).Then the alkali species and other components in the coal ash were quantified by X-ray fluorescence(XRF)for evaluating the ash slagging and fouling tendency.Apart from this,FactSage was adopted to simulate the occurrence and transformation of alkali species during coal thermal conversion ending at various temperatures.The findings indicate that the treated coals are superior to the parent ones in terms of certain remarkable changes via HTP.The moisture,oxygen and sulfur of the hydrothermally treated coals decline obviously,while the calorific value rises sharply.HTP could reduce the alkali species to less than 2%(%,by weight,equivalent to Na2O in dry ash),with a maximum removal ratio of 88.9%,lowering the ash slagging and fouling tendency.The proposed mechanism of HTP was that the alkali species in coal matrix became released due to the breakage of the coal functional groups and micropores during HTP.

Flux mechanism of compound flux on ash and slag of coal with high ash melting temperature

The melting temperature of Z coal ash was reduced by adding calcium–magnesium compound flux(WCaO/WMgO=1). In the process of simulated coal gasification, the coal ash and slag were prepared. The transformation of minerals in coal ash and slag upon the change of temperature was studied by using X-ray diffraction(XRD). With the increase of temperatures, forsterite in the ash disappears, while the diffraction peak strength of magnesium spinel increases,and the content of the calcium feldspar increases, then the content of the amorphous phase in the ash increases obviously. The species and evolution process of oxygen, silicon, aluminum, calcium, magnesium at different temperatures were analyzed by X-ray photoelectron spectroscopy(XPS). The decrease of the ash melting point mainly affects the structural changes of silicon, aluminum and oxygen. The coordination of aluminum and oxygen in the aluminum element structure, e.g., tetracoordinated aluminum oxide, was changed. Tetrahedral [AlO4] and hexacoordinated aluminoxy octahedral [AlO6] change with the temperature changing. The addition of Ca2+ and Mg2+ destroys silica chain, making bridge oxide silicon change into non-bridge oxysilicon;and bridge oxygen bond was broken and non-bridge oxygen bond was produced in the oxygen element structure. The addition of calcium and magnesium compound flux reacts with aluminum oxide tetrahedron, aluminum oxide octahedron and silicon tetrahedron to promote the breakage of the bridge oxygen bond. Ca2+ and Mg2+ are easily combined with silicon oxide and aluminum oxide tetrahedron and aluminum. Oxygen octahedrons combine with non-oxygen bonds to generate low-melting temperature feldspars and magnesite minerals, thereby reducing the coal ash melting temperatures. The structure of kaolinite and mullite was simulated by quantum chemistry calculation, and kaolinite molecule has a stable structure.

Coal Ash Slag Penetration Behavior on Cr_2O_3-Al_2O_3-ZrO_2 Bricks

The penetration behavior of different kinds of coal ash slags into chrome corundum bricks was studied by cup test. As a preliminary attempt,the oxides of Fe2O3 and MgO were added into coal ash to reduce the erosion of refractories. Different cup tests were carried out to study coal slag erosion to the refractories. FactSage was used to simulate the phase diagram of the main chemical compositions in coal ash and in the refractories. Both results agreed with each other. The results show that the elements in coal slag can penetrate into bricks and the penetration deepens with the duration increasing; it is difficult for Fe but easier for Ca and Si to penetrate into bricks; different kinds of melting coal ashes penetrate into refractories differently and the penetration depth of silicon and calcium can be significantly reduced by adding oxides into coal ash.

Type Selection of Burning Equipment for Slagging-Coal Boilers

The type selection of burning equipment for boilers is affected significantly by the slagging characteristics of coal. Based on the engineering statistics method, the designed furnace parameters are obtained from the 600-MW and 1 000-MW boilers with tangential firing and wall firing. The power and arrangement of the burners are analyzed. Their impacts on slagging on heating surfaces and the carbon contents in the ash and cinders are also discussed. Thermal parameters of furnace are recommended for boilers of 600 MW and 1 000 MW firing slagging coal in the design. The static or rotary classifier should be the first choice for the pulverizing system.

A New Distinguish Method of Blending Coals Slagging Characteristic

The slagging characteristic of coal effects the safe operation of boiler unit directly, the study on coal slagging is paid more and more attention by scholars of the world. Because of the complexity of coal characteristic, the blending coals slagging characteristic is more complex than single coal. The study method of blending coals characteristic is the same as the single coal method, but the simple method can’t distinguish the blending coals slagging characteristic well and truly. This paper gives the new distinguish method of blending coals slagging characteristic based on experimentation condition, it is the rate of slag and furnace refuse. The rate of slagging on furnace wall and the refuse on furnace bottom has utilized to distinguish the slagging characteristic of coal. The result shows that the rate of slag and furnace refuse method has better veracity.

煤气化炉渣对煤矸石膏体充填材料性能影响

目的利用煤气化炉渣颗粒的球形特征,研究其对煤矿采空区膏体充填材料流动性和强度的影响规律,并分析其影响机理。方法以质量分数为85%的煤矸石骨料充填膏体为对照组,煤气化炉渣等质量取代膏体中煤矸石细骨料10%,20%,30%,40%,50%,分别测试新拌膏体泌水率、坍落度、扩展度、流变屈服应力和塑性黏度等浆体性能,同时测试膏体结石体抗压强度。结果结果表明,随着炉渣取代率增加,膏体泌水率增加,坍落度和扩展度增加,流变屈服应力和塑性黏度减小;与对照组相比,炉渣取代率为10%时,膏体屈服应力和塑性黏度分别降低16.7%,1.6%;与10%取代组相比,炉渣取代率为20%时,膏体屈服应力和塑性黏度分别降低47.4%,15.0%,降低速率大幅增加;继续增加炉渣取代率,膏体屈服应力和塑性黏度又缓慢增加;膏体结石体早期强度(3,7 d)随着炉渣取代率增加而小幅降低,后期强度(28,60 d)无显著变化。结论煤气化炉渣作为骨料取代膏体充填材料中的煤矸石细骨料,可以改善新拌膏体流动性,取代率达到20%时,可以充分发挥球状炉渣颗粒在多棱角煤矸石骨料间的滚珠润滑作用,减小矸石骨料机械咬合,大幅降低充填膏体屈服应力和塑性黏度;且炉渣对充填膏体结石体后期强度无显著影响。

碎煤熔渣加压气化过程数值模拟分析

碎煤熔渣加压气化技术(British Gas-Lurgi,BGL)取缔了炉篦,干法排渣改液态排渣,气化性能显著改善。为揭示BGL煤气化本质结构特征,支撑企业气化装置性能再提升,论文采用数值模拟方法构建了热力学平衡模型、煤气化动力学模型和欧拉多相流模型,并验证了模型合理性。模拟研究表明:与鲁奇煤气化相比,气化平衡温度由795℃(鲁奇炉)提高到1029℃,水蒸气分解率由32.66%提高到93.12%;床层最高温度由1110℃提高至1837℃,远高于煤灰流动温度1210℃,提高了气化强度,保证了液态排渣;BGL煤气化反应在炉膛下部基本完成,仅有少量水蒸气参与变换反应,粗煤气中的CH_(4)基本来自煤热解;气化炉床层腾涌波动,增强了传热传质;喷嘴射流冲击煤焦颗粒,形成向中心区延伸的椭球形燃烧回旋区,成为BGL煤气化的重要功能单元,实现一次布气,为气化层和熔渣池提供热量;熔渣池中液渣上下回旋流动,有利于降低熔渣残碳,保障顺畅排渣。

西北干旱露天煤矿排土场土壤重构与水盐运移机制

矿山排土场生态修复是煤矿露天开采面临的重大环境问题,是制约建设绿色露天煤矿的重要因素。土壤重构是排土场生态修复的重要步骤,以新疆为代表的西北煤炭基地,水资源短缺,盐碱化突出,土壤水盐运移是决定土壤重构是否成功的关键指标。目前研究集中在表层土壤重构改善土壤养分促进植物生长,针对保水控盐的功能化土壤重构的研究甚少,对不同土壤重构方式下的水盐运移机制尚不明晰。研究立足新疆煤炭资源禀赋特征,从煤炭循环经济的角度出发,采用能源化工副产物煤气化渣(CGS)作为重构材料,通过毛细水上升-蒸发试验,分析CGS重构后水盐垂向运移和水分供给能力,通过Van Genuchten模型拟合土壤水分特征曲线,分析CGS重构后土壤持水能力,研究CGS作为含水层重构材料的可行性。采用煤矿开采伴生岩石矿物红泥岩作为重构材料,通过土柱入渗蒸发试验,分析红泥岩重构后不同土壤深度的水盐变化情况,研究泥岩作为隔水层重构材料的可行性。结果表明,CGS重构改善土壤质地,优化孔隙结构,促进了土壤水盐运移,毛细作用增强,促进了下层水分向上供给,同时也增加了盐分表聚,重构改变土水特征曲线参数,增加了饱和含水量θ_(s),降低了参数a和n,改善了土壤持水性能。CGS添加量越高,细渣质量分数越大,效果越明显。CGS作为重构含水层材料具有可行性。红泥岩黏粒和次生矿物含量高,孔隙结构丰富,物理吸附性良好,重构后0~24 cm深度下土壤含水率高于对照组,蒸发后的盐分在20~24 cm达最高值,红泥岩有效阻隔了盐分上移。红泥岩作为重构隔水层材料具有可行性。研究以期探索出一条适合西部煤炭基地排土场土壤重构模式。

煤气化渣结构组成及其主要金属元素赋存形态

煤气化渣的减量化、资源化和无害化是目前煤化工行业的研究热点,对其物理化学特性及重金属含量与环境风险的研究是实现以上目标的基础。以宁东基地某煤化工生产企业的煤气化渣为研究对象,研究了粗渣和细渣的结构组成及主要金属元素赋存形态与环境风险。结果表明,煤气化渣由残炭和灰分(主要成分为SiO_(2)和Al_(2)O_(3),质量分数分别为50%和15%左右)组成。粗渣灰分含量高(质量分数>90%)且颗粒致密光滑,细渣残炭含量高(质量分数约20%)且孔隙丰富。含量高于500µg/g的金属元素主要富集在粗渣中,低于200µg/g的金属元素在细渣中富集。细渣中金属元素稳定性较低,特别是Cd,其非稳定态占比高于70%,且风险评价指数为34.16,环境风险高。本研究旨为煤气化渣的资源化和无害化处理提供基础数据。

煤气化渣气流分级提炭分质试验

煤气化渣提炭分质是实现其减量化、资源化、高值化利用的关键。基于此,提出研磨破碎-气流分级的干法提炭工艺,利用研磨使气化渣中炭灰结合物解离,再利用气流分级机内离心力和气体曳力作用,将解离所得的细颗粒进行高效分离。通过设计均匀试验并对各影响因素进行回归分析,获取优选试验条件并对该试验条件下的提炭效果进行验证。结果表明,气流分级提炭受多因素耦合作用影响,其中分级机频率和引风机频率是影响提炭效果的关键。均匀试验优选条件为分级机频率175 Hz、引风机频率5 Hz,喂料螺旋频率5 Hz,二次风口全开;该条件下所得富炭产品的收率为25.86%,烧失量49.76%,较原气化渣烧失量提高了26.91%,与试验预测值(49.64%)较一致,且试验效果明显优于未研磨破碎直接气流分级的气化渣。优选条件下气流分级得到的富炭产品的平均粒径(Dav)为5.95μm,满足橡胶补强填充料的粒度要求,其热值为16.73 MJ/kg,亦可作为细粉燃料等使用。同时,气流分级可实现较好的气化渣脱炭效果,所得脱炭渣烧失量低于10%,有利于其在建材等领域应用。研磨破碎-气流分级方法可实现气化渣的提炭分质,有利于其下游利用。

大型燃煤锅炉中含Na/Cl/S组分的演变与受热面结渣倾向的数值模拟

提出了一种考虑煤中含Na/S/Cl组分多步释放、气相组分相互作用、气-固反应以及盐蒸气冷凝耦合灰颗粒黏附的结焦模型,以预测炉内受热面气态碱金属组分冷凝行为、受热面结焦风险以及炉膛出口Na/S/Cl组分分布特性。结果表明:炉膛出口气态含Na组分主要以NaO_(2)、NaCl、Na_(2)SO_(4)和NaOH形式存在;最上层燃烧器至分离燃尽风(SOFA)喷口区域、最下层燃烧器至冷灰斗转角区域的水冷壁结焦风险高;炉膛出口区域后屏过热器底部颗粒黏附位置相对集中,炉内辐射式过热器结焦速率远高于气态钠盐冷凝速率,对流受热面颗粒沉积速率约是钠盐蒸气冷凝速率的3~4倍。

液态排渣锅炉全烧和大比例掺烧高碱煤运行优化

为掌握液态排渣锅炉全烧和大比例掺烧高碱煤的关键参数和运行经验,基于某电厂300 MW等级液态排渣锅炉进行了长期工程试验,对可能存在的燃烧组织、NO_(x)控制、排渣和沾污等问题进行分析,针对性的对燃烧系统、热物改性系统和排渣系统进行了改造。并进行了长期的运行数据记录和关键参数记录,在全烧和高比例掺烧高碱煤30万t后,锅炉各项运行参数正常。工程试验证明:该电厂300 MW等级液态排渣锅炉经升级优化后对高碱煤的的适应能力极强,在燃煤组分w(Al_(2)O_(3))<25%、w(Fe_(2)O_(3))<15%、12%<w(CaO)<30%、硅铝比大于1.7、碱酸比大于0.5时均可以保证机组正常运行且没有明显沾污;燃用高碱煤后可有效降低第一级受热面入口烟气温度至设计值以下,避免锅炉第一级受热面结渣情况,NO_(x)生成量也较燃用原设计煤种下降超30%。

煤气化渣活化过二硫酸盐和过一硫酸盐降解苯酚的比较

以固体废弃物煤气化渣(CGS)作为活化剂,构建了煤气化渣/过二硫酸盐(CGS/PDS)和煤气化渣/过一硫酸盐(CGS/PMS)体系,通过场发射扫描电子显微镜表征CGS的微观结构和元素组成,使用傅里叶红外光谱仪和X射线光电子能谱仪表征CGS表面官能团,考察了CGS投加量、PDS浓度、PMS浓度、初始pH等因素对降解苯酚的影响,推测了活化路径,探究了氧化机理。结果表明,CGS中Fe元素含量达11.9%且含有多种官能团,随着CGS投加量的增加,PDS和PMS对苯酚的降解效率逐渐增大。当CGS投加量为3.0g/L时,1.0mmol/L PDS反应60min后对苯酚的降解率达97.82%,0.4mmol/L PMS反应60min后对苯酚的降解率达98.88%。两种体系对苯酚的降解率均在p H=3时最高。共存Cl-对两个体系降解苯酚均表现出促进作用,而共存NO_(3)^(-)、SO_(4)^(2-)、HCO_(3)^(-)对苯酚的降解产生抑制作用。CGS/PDS体系降解苯酚过程中产生了·SO_(4)^(-)和·OH,而CGS/PMS体系产生了·SO_(4)^(-)、·OH和·O_(2)^(-),但两个体系对苯酚的降解均以·SO_(4)^(-)占主导地位。研究结果可为固体废弃物煤气化渣高价值应用提供指导,为煤气化渣进一步应用于水污染控制提供理论依据。

电石渣和煤矸石对型煤固硫性能的影响及作用机制研究

研制高效低成本的耐高温固硫剂和添加剂有助于解决型煤高温燃烧环境下钙基固硫产物的分解问题。电石渣和煤矸石属于典型的工业固体废弃物,利用固废作为添加剂制备固硫型煤有助于降低固硫型煤成本和挖掘固废资源价值,发挥这两种固废中矿物组分协同作用可改善高温条件下型煤固硫效果。开展了电石渣和煤矸石分别作为固硫剂和添加剂制备环保型煤的研究,考察了固硫剂种类(碳酸钙、氧化钙、氢氧化钙和电石渣)、钙硫物质的量比(1.5~4.0)、燃烧温度(900℃~1300℃)、煤矸石用量(2%~7%)对型煤固硫效果的影响。通过型煤燃烧评价实验发现,仅用电石渣作为固硫剂,在钙硫物质的量比为3.0时制得的型煤在燃烧温度低于1000℃时固硫率能达到80%以上,燃烧温度提高到1300℃时型煤固硫率下降40%,结合分析表征数据发现主要原因是固硫产物硫酸钙的高温分解。添加的煤矸石在高温条件下被电石渣组分活化后起到辅助固硫作用,当添加的煤矸石的质量分数达到5%时型煤的固硫率能维持在60%以上,在此基础上增加煤矸石用量并不能明显提升型煤固硫率。通过固硫产物热稳定性研究并结合分析表征数据发现,高铝煤矸石灰渣活性组分发生高温反应生成硫铝酸钙、钙黄长石、硅酸三钙等耐高温稳定物相,在一定程度上抑制了CaSO_(4)的分解,从而提高了型煤的高温固硫率。