An Experimental Study on Binderless Briquetting of Low‐Rank Coals

The potential of binderless briquetting as a means of transforming low‐rank coals into low moisture high grade solid fuel products has been studied. Using two dried low‐rank coals, binderless briquettes with high mechanical strength have been successfully produced through mechanical compression. An increase in heating value was achieved as a result of moisture reduction in the briquettes compared to as‐received coals. The residue moisture content in the briquettes had a predominant effect on briquetting characteristics and there existed an optimum moisture content for the maximum briquettes strength. The chemical structure and wettability of binderless briquettes were analyzed using FTIR and contact angle measurement. The results showed that hydrophobicity and chemical structure significantly affected the briquette properties.     

The effect of different treatment conditions on biomass binder preparation for lignite briquette

The tests of treating rice straw with sodium hydroxide, lime and sulfuric acid were individually done and the possibility of using a binding agent based on rice straw as lignite briquette binder was studied. In this study, the lignite from Pingzhuang coal basin was selected as the coal for briquetting. It was found that the type of chemical agents and their concentration were the main factors influencing preparation of a binding agent based on rice straw. The binding mechanisms of a rice straw-based binder containing sodium hydroxide were quite different from that made with lime. The experiment showed that the rice straw treated with sulfuric acid could not be used as a briquette binding agent. Additionally, it made clear that comprehensive binders, which were prepared by adding bentonite, coal tar and/or polypropylene amide into rice straw-based binder, would have waterproof property and would benefit the quality of briquettes.     

Molasses and air blown coal tar pitch binders for the production of metallurgical quality formed coke from anthracite fines or coke breeze

The effect of the type and the amount of hardeners, such as ammonium nitrate, ammonium carbonate and nitric acid on the molasses bonded briquettes prepared from anthracite fines or coke breeze were investigated. Amongst the hardener studied the best results were obtained with 2.5% ammonium nitrate hardener. The briquettes produced with this hardener were highly water resistant but not waterproof and their tensile strengths were not adequate to be used as a substitute for the metallurgical coke. Therefore, the briquettes were prepared with molasses containing 2.5% ammonium nitrate hardener and air blown coal tar pitch blended binder. When the blended binder was used for the production of anthracite fines or coke breeze briquettes, after curing at 200 °C for 2 h, they became waterproof and their tensile strengths were found to be sufficient to be used as a substitute for coke oven coke. The briquettes after curing could be directly charged into the blast furnace without carbonizing them at high carbonization temperatures. Since molasses and coal tar pitch, are relatively cheap and readily available materials, the process investigated could be economical way of producing high quality formed coke.     

粉煤成型机理研究进展

综述了粉煤成型机理研究进展。褐煤无粘结剂成型机理有沥青、腐植酸、毛细孔等多种假说,这些假说都认为,煤“自身粘结剂”的丰厚 成型的重要基础;粉煤在粘结剂成型过程中,煤与粘结剂间相互润湿是成型的前提条件,进而依靠内聚力和粘附力使粉煤成型。本项研究将为开发粘结剂及成型新工艺提供理论依据。     

型煤与焦粉型焦粘合剂的研究及应用

探讨了型煤粘合剂的粘结机理 ,介绍了几种主要粘合剂的分类 ,重点论述了WIN -1型民用与锅炉型煤粘合剂、WIN - 2超微粉造气型煤粘合剂及WIN - 3焦粉型焦粘合剂的研究和应用情况 ,利用这些粘合剂生产的锅炉型煤、造气型煤、焦粉型焦等产品均达到了应用要求     

粉煤成型机理研究进展

阐述了无黏结剂成型机理和粉煤有黏结剂冷压成型机理,说明无黏结剂成型机理主要包括沥青质假说、腐植酸假说、毛细管假说、胶体假说以及分子黏合假说;粉煤有黏结剂冷压成型时,黏结剂与粉煤的作用力主要有固体桥联联结力、静电吸引力、液体桥联联结力;两种机理均无法全面解释型煤成型机理和指导型煤生产实践。在此基础上,提出粉煤成型机理研究新方法,可从了解型煤微观结构入手,研究型煤硬度、弹性、塑性和表面物理化学性质等原煤自身性质以及粒度、水分、烘干温度和成型压力等工艺参数与不同黏结剂作用时型煤微观结构形态及变化规律,建立型煤制备过程/工艺-微观结构-宏观性质之间的关系来探寻粉煤成型机理。     

BCFC的制备和成型机理及燃烧特性

通过实验确定了生物质煤基燃料炭(BCFC)的制备工艺,研究了BCFC的成型机理和燃烧特性.结果表明,BCFC的制备工艺是将禹州煤、玉米秸秆和黏结剂按照81∶6∶13的质量比混合成型,再经700℃炭化处理.生物质型煤的内部结构、禹州煤和有机黏结剂的黏结性是BCFC成型的保证.市售燃料炭在燃烧初期燃烧强度较大,但持久性逊于BCFC,这与二者挥发分、固定碳和发热量的差异有关.     

添加浮选镁砂颗粒和Al2O3细粉对方镁石-尖晶石砖性能的影响

以烧结镁砂、浮选镁砂、电熔镁铝尖晶石和煅烧Al₂O₃细粉为主要原料,以木质素磺酸钙为结合剂,经混练、成型、1 650℃烧成制备了方镁石-尖晶石砖,主要研究了以浮选镁砂颗粒替代普通烧结镁砂颗粒以及在此基础上外加不同量煅烧Al₂O₃细粉（质量分数分别为0、3%和5%）对方镁石-尖晶石砖性能的影响。结果表明：1)以浮选镁砂颗粒替代普通烧结镁砂颗粒制备的方镁石-尖晶石砖,显气孔率和常温耐压强度降低,体积密度、抗热震性、高温强度和高温韧性提高。2)在以浮选镁砂颗粒替代普通烧结镁砂颗粒制备的方镁石-尖晶石砖中,随着煅烧Al₂O₃细粉引入量的增多,显气孔率和常温耐压强度降低,体积密度、抗热震性、高温强度和高温韧性提高。     

Briquetting the carbon phase from the sludge ponds at the Anzhersk deposit

The briquetting of coal slurries from the Anzhersk deposit in the Kuznets Basin is investigated. Petroleum binder and sodium lignosulfonate are employed. The solid carbon phase from the sludge ponds (ash content up to 35%) has adequate briquetting properties when petroleum binder is added. The use of sulfite waste liquor at pressures of 80–100 MPa yields mechanically strong briquets that require additional water protection.     

Production of fuel briquettes from anthracite fines

Experimental data on the development of a technology for the production of fuel briquettes from anthracite fines, slack coal, and coal slurries available in the Rostov oblast are presented. The effects of the moisture content and particle size distribution of the coal components, the moisture content of the charge, the composition of a binder, the compacting pressure, and the regime of hardening on the technical properties of the fuel pellets were studied. The possibility of obtaining water-resistant briquettes was demonstrated.     

晋城高强度防水气化型煤的研究

研究出ＭＪ１０粘结剂及ＭＪ１０－ＭＪ１１复合粘结剂,并用于晋城粉煤及其他几种粉煤,制出了高强度防水型煤,革制备工艺简便,不需要烘干工序,ＭＪ１０－ＭＪ１１复合粘结剂用于晋城粉煤成型,已取得了性成型和气化试验的成功,为发展可长途运输的气化型煤提供了技术途径。     

鹤岗烟煤粉煤生产气化用型煤的研究

开发出一种ＭＪ３有机粘结剂，其粘结力强，价格不高。将ＭＪ３与彭润土组成复合粘结剂用于鹤岗高挥发分烟煤成型取得了小试与扩大试验成功，制出了机械强度较高，防水的型煤，还用１０ｔ型煤在煤气发生炉上进行了气化，能正常地产出燃料气。     

Densification of water hyacinth — basic data

The briquette-forming ability of water hyacinth (WH), a plant with prolific growth, to produce a fuel wood substitute or for further processing has been investigated. Compared to straw and sawdust, WH can undergo binderless briquetting. Pressure, water content and temperature have a strong influence on the briquette-forming ability of WH. Laboratory trials showed that optimal conditions are achieved between compaction pressures of 80 and 200 MPa, temperatures between 70 and 80 °C and water contents between 8 and 12 wt%. Die ram-extrusion and pellet-mill briquetting presses allow the compaction of WH with acceptable throughputs and with a specific energy consumption of 180 MJ t^?1. The produced briquettes, with a density of 1400kg m^?3 and a compression rate of 1:14, proved to be abrasive-resistant and showed an acceptable compressive strength. The re-expansion behaviour of the briquettes was moderate. The extractable matter of WH does not contribute to the briquette strength. No experimental indication of lignin softening could be found.     

干化污泥型煤抗压强度的实验研究

利用微波干燥脱水污泥制备型煤粘结剂,与粉煤混合压制成型煤。通过正交试验考察成型压力、干化污泥含水率及添加比例对型煤抗压强度的影响。结果表明：微波干化的污泥型煤较粘土型煤的抗压强度大;成型压力、干化污泥含水率及添加比例均为型煤抗压强度的显著因素,各因素优化范围：成型压力为25～30MPa,干化污泥水分为40％左右,干化污泥添加比例为20％～30％。     

利用菱镁矿粉状尾矿制备氧化镁工艺研究

针对制备高纯镁砂的菱镁矿粉状尾矿,采用菱镁矿精制-压球-轻烧工艺,可直接得到合格的镁砂产品。在菱镁矿精制过程中,添加球团添加剂,使后续工艺轻烧过程中菱镁矿保持球团形貌特征,避免球团大量粉化造成竖窑堵塞。通过冲击测试得到的轻烧球团强度,即从0.5 m坠落次数可达10次,粉体活性＜230 s,烧失率＜0.1%。     

以瘦煤为主要原料制备型焦的配煤方案研究

研究了以平顶山八矿瘦煤为主要原料制备型焦的配煤方案,实验时首先对所用的各原料煤破碎、筛分,再进行工业分析,然后根据配煤原理制定配煤方案。煤混配后在成型机上成型,得到的型块通过冷压成型工艺制成型焦,随后对制得的型焦测其抗压强度和对CO2的化学反应性。结果表明：以瘦煤为主要原料制备型焦的最佳配煤方案是：90%瘦煤配入10%的肥煤。     

湿料低压成型制防水生物质型煤的研究

介绍了运用湿料低压成型工艺制备生物质型煤的工艺流程及研究过程,生产中研发了具有免烘干、防水、固硫三重功效的TX添加剂;阐述了层燃锅炉对煤质的要求、生物质型煤的配制及在锅炉上的运行操作情况;测试结果表明,湿料低压成型技术投资少、生产成本低,所制型煤燃烧效率高、环保效果好。     

煤与粘结剂的相互作用和型煤抗压强度的关系

煤的润湿性与型煤抗压强度相关。用于表征煤的润湿性方法有煤与淀粉粘结剂的接触角、粘合功、煤的润湿临界表面张力等。研究证明,随着煤化程度的升高,煤与淀粉粘结剂接触角变小,粘合功增加,粉煤的润湿性改善,型煤抗压强度得以提高。另外,煤的润湿临界表面张力越大,煤的润湿性越好,型煤抗压强度也就越高。     

黏结剂对长焰煤制备民用洁净焦炭强度的影响

在我国广大农村地区,居民仍使用劣质散烧原煤,严重破坏了大气环境。提供优质的煤基洁净燃料是从源头上解决劣质煤散烧所带来环境问题的重要手段之一。但由于传统民用炉具为层燃式,对所用燃料具有强度和块度的要求。因此,如何保证燃料的成型与强度是一个关键问题。基于此,本文以长焰煤为原料,与复合助剂先经冷压成型,再通过热解制备得到洁净焦炭。同时,系统地研究了复合黏结剂添加量、热解温度等对洁净焦炭强度的影响。结果表明：加入1%聚乙烯醇（PVA）、30%洗油渣（WOR）,在800℃下可得到抗碎强度为94.7%的洁净焦炭,可满足相应的强度要求。复合添加剂中的PVA为冷态黏结剂,其遇水会在煤粒间形成高黏性网状胶体,促使煤颗粒之间黏结,保证其冷态强度。而WOR为热态黏结剂,其在高温热解过程将转化为高黏结性的类胶质体,将原本松散的、无黏结性的惰性颗粒黏结,最终形成高强度的民用洁净焦炭。该研究对高强度民用洁净焦炭的制备提供理论指导。     

Effect of the pyrolysis process on the physicochemical and mechanical properties of smokeless fuel briquettes

A greater understanding of the physics and chemistry of lignite–biomass briquetting could lead to better briquette performances and cost-effectiveness making these fuels more attractive to both producers and consumers. With this aim, chars obtained from different low rank coals and biomasses (sawdust, straw, olive stone and almond shell) were used to prepare smokeless fuel briquettes and their physicochemical and mechanical properties were studied depending on the pyrolysis conditions. Coal was pyrolysed at temperatures between 500 °C and 700 °C and the temperature chosen to carry out pyrolysis was 600 °C due to the lowest content of sulphur per thermie in the pyrolized material. In order to study the influence of the pyrolysis process on the properties of the briquettes, biomasses were pyrolysed separately at 400 °C and 600 °C and together with the coal at 600 °C of temperature. The materials pyrolysed at 600 °C showed a lower content of volatile matter and a higher calorific value than the standard levels reported in the literature for materials to prepare smokeless briquettes. The briquettes were prepared by mixing the pyrolysed materials with humates as binder and Ca(OH)₂ as sulphur sorbent. The briquetting process was followed by FT-IR, scanning electron microscopy (SEM), CO₂ adsorption and the mechanical properties were tested evaluating their impact resistance, water resistance and compression strength. The best briquettes with respect to the mechanical properties were those prepared with coal and biomasses co-pyrolysed at 600 °C although some of them fixed a higher percentage of sulphur during pyrolysis due to the metal content of the biomasses.