Simulation Research on Coal-Water Slurry Gasification of Oil-Based Drill Cuttings Based on Fluent

In this paper,based on Fluent software,a five-nozzle gasifier reactor was established to simulate the gasification process of oil-based drill cuttings coal-water slurry.The influence of concentration and oxygen/carbon atomic ratio on the gasification process of oil-based drill cuttings coal-water slurry was investigated.The results show that when the oxygen flow is constant,the outlet temperature of gasifier decreases,the content of effective gas increases,and the carbon conversion rate decreases with the increase of concentration;When the ratio of oxygen to carbon atoms is constant,the effective gas content rises and the temperature rises with the increase of the concentration,and the carbon conversion rate reaches the maximum value when the concentration of oil-based drill cuttings coal-water slurry is 65%;When the concentration is constant,the effective gas content decreases and the outlet temperature rises with the increase of the oxygen/carbon atom ratio,and the carbon conversion rate reaches 99.80%when the oxygen/carbon atom ratio is 1.03.It shows that this method can effectively decompose the organic matter in oilbased drill cuttings and realize the efficient and cooperative treatment of oil-based drill cuttings.

Effect of the benzene ring of the dispersant on the rheological characteristics of coal-water slurry:Experiments and theoretical calculations

In this study,low-rank coal-water slurry(LCWS)was prepared using polyoxyethylene dodecylphenol ether(PDPE)and polyoxyethylene lauryl ether(PLE),respectively.A combination of experiments and simulations was used to investigate the pulping properties and microscopic mechanism of the LCWS samples prepared using the two agents,so as to explore the influence of benzene ring on the performance of dispersant.The results of the LCWS preparation experiments revealed that the pulp-forming performance of PDPE exceeded that of PLE.When LCWS concentration is 62%,64%,and 66%,the apparent viscosity corresponding to PDPE is 247.80,504.17,and 653.10 mPa·s,and the apparent viscosity corresponding to PLE is 548.10,1470.61,and 1549.98 mPa·s,respectively.The C_(1000)(When the apparent viscosity is 1000 mPa·s,the corresponding concentration of LCWS is defined as C_(1000))values of PDPE and PLE are 67.60%and 62.95%,respectively.In addition to the van der Waals forces and hydrogen bonds between the PDPE and/or PLE molecules and coal,the benzene rings of PDPE presentπ-πstacking effect with the aromatic rings of coal.That could facilitate and strengthen the adsorption of PDPE on coal,which would be conducive to further improving the dispersion of coal particles.The two dispersants have no significant difference in effect on the pyrolysis of LCWS.The simulation results indicated that the times for PDPE and PLE molecules to reach flat adsorption state on coal are approximately 290 and 565 ps,respectively.The self-diffusion coefficient(D)of the PDPE and PLE on coal is 3.16 x 10^(-6)and6.57×10^(-6)m~2/s,respectively,and their interaction energies with coal are 785.71 and 648.60 kcal/mol,respectively.The results of the simulation calculations demonstrated that PDPE adsorbed on coal easier than PLE,and its binding is more stable than that of PLE owing to theπ-πstacking effect,which is conducive to uniform dispersion of coal in solution.The simulation results confirmed the experimental results.

Effect of the high-power electromagnetic pulses on the reactivity of the coal-water slurry in hot environment

An effect of the high-power electromagnetic pulses onto the droplet of coal-water slurry inside the furnace was investigated.In contrary to the previously investigated laser-induced fuel atomization that occurs at the room temperature,the pre-heated(to 400 K)slurry becomes dry enough to prevent the explosion-like steam formation.Thus,fuel does not atomize and the ignition does not accelerate.Furthermore,the absorption of several laser pulses leads to evident sintering of irradiated surface with following increase of the ignition delay time for up to 24%.Variation of the pulse energy in range 48-118 mJ(corresponding intensity up to 2.4 J·cm^-2)leads to certain variation of the increase of ignition delay.The strong pulsed overheating of the coal water slurry which does not initiate the fine atomization of the fuel generally makes its ignition longer.

Combustion and Sulfur-fixing Performance of Pulping Black Liquor Coal-water Slurry

The effects of adding pulping black liquor and other additives to coal-water slurry(CWS) on the sulfur-fixing performance of the resultant mixture(pulping black liquor coal-water slurry) were evaluated. The experimental results demonstrated that the ash content of the black liquor coalwater slurry decreased as the addition of pulping black liquor in the mixture increased. Nevertheless, the addition amount should be appropriately selected to ensure that the black liquor coal-water slurry had a moderate calorific value. Addition of black liquor improved the combustion performance of CWS by lowering the ignition point and stabilizing the combustion process; moreover, the sulfur-fixation ratio after combustion increased by 12 to 16 percentage points than that of CWS, and the content of high-melting-point salt in the ash from CWS after adding black liquor was low. The sulfur-fixing ratio of CWS after adding a sulfur-fixing agent was effectively increased by 25 to 30 percenatge points, but with compromise of the fluidity and stability of the CWS; thus, the addition amount of a sulfur-fixing agent should be optimized.

CORRECTION OF WALL SLIP EFFECTS AND RHEOLOGICAL MEASUREMENT OF HIGH CONCENTRATED COAL WATER SLURRY

Coal-water slurry, a ncw liquid fuel, began to appcar during the world-wide petroleum crisis in the seventies of this century. Its applications to substitute petroleum drew great attention on the investigations of its preparation, combustion and transportation, etc. The rheological behavior is an important quality index for the fuel. However, the conventional viscosimeters designed for true fluids are not suited to the high concentrated slurry due to the complicated rheological bchavior. A special viscosimeter of tube type was rcpresented, which was designed and set up by the authors for the measurement of the theology of high concentrated coal-water slurry and experiments were conducted with two kinds of slurries from P. R. China. In consideration of the wall sliD effects the correction of the experimental data were made.

基于卡曼滤波的矿浆浓度计设计

设计了一种基于卡曼滤波的γ射线浓度计。通过分析射线浓度计的测量原理,建立了射线强度与矿浆浓度的关系式;利用卡曼滤波对射线强度进行最优估计,以抑制测量结果的扰动;最后通过最小二乘法分段拟合计算对应的浓度。结果表明,该浓度计测量及时、准确,最大误差0.328个百分点,均方根误差0.194个百分点,测量精度得到有效提高。

基于煤颗粒−结合水复合相的水煤浆导热系数预测模型

水煤浆气流床气化是目前大型先进煤气化技术之一,提升水煤浆气化效率有助于推动煤炭清洁高效利用。水煤浆预热技术被认为是提高煤气化能源利用效率的关键技术之一。目前,复杂液固悬浮液导热系数的变化规律和内在机理仍未被完全认识。导热系数是介质流动换热的重要基础参数,表征着其在稳态导热过程的导热能力。利用瞬态热线法测定不同温度下相同质量分数水煤浆的导热系数,实验结果表明:温度越高,导热系数越高。在室温下测定不同质量分数下水煤浆的导热系数,实验结果表明可以分为2个阶段:质量分数从51%增大到58%时为下降区,导热系数快速下降,由0.401 W/(m·K)降至0.358 W/(m·K);而质量分数继续增加,从58%到67%时为恒定区,导热系数基本保持在0.358 W/(m·K)。基于实验结果,综合考虑平行模型、麦克斯韦模型、广义自洽模型等复合材料模型,提出煤颗粒−结合水复合的水煤浆导热系数平行预测模型。水煤浆中的水分包含自由水和结合水,结合水会和煤颗粒形成煤颗粒−结合水复合相,将水煤浆视为复合相和自由水相组成的两相复合材料。在下降区,随着煤颗粒质量分数的增加,自由水相减少,复合相不变,水煤浆导热系数快速降低;在恒定区,随着煤颗粒质量分数的进一步增加,复合相中的结合水量减少,但复合相的导热系数基本维持稳定。

豆浆固形物含量及浆液深度对腐竹生产及品质的影响

目的:确定腐竹高效优质生产适宜的豆浆固形物含量和浆液深度。方法:探究豆浆固形物含量和浆液深度对腐竹得率、成膜速率、营养成分、机械性能、蒸煮损失率和复水比等的影响。结果:当豆浆固形物含量为6%,豆浆浆液深度为6 cm时,腐竹得率(34.68%)和营养物质含量最高,其蛋白质含量为51.05%,脂肪含量为23.42%,且抗拉强度和复水性较好,分别为3.74 MPa和3.80 g/g。结论:综合考虑腐竹得率、成膜速率和食用品质等指标,建议采用豆浆固形物含量6%,豆浆浆液深度6 cm进行腐竹的高效优质生产。

基于蒙特卡罗模型的高浓度浆液细度在线测量

近年来颗粒粒径测量问题受到了国内外的广泛研究。针对燃煤电厂高浓度脱硫石灰石浆液细度在线测量,将基于蒙特卡罗方法的声衰减模型拓展至高浓度范围,高浓度蒙特卡罗模型(HC-MCM)预测衰减系数与实验测量值相吻合。构建HC-MCM矩阵用于颗粒粒径分布的反演可减小计算时间,且差分进化算法的计算结果与设定粒径和分布宽度的相对误差小于1%。搭建基于透射和反射法的双模式超声检测装置并开发软件测量系统,加工适用于高浓度浆液细度测量的透射传感器和超声探针,依托燃煤电厂完成长达168 h的浆液细度在线测量实验。结果表明,两种模式超声衰减谱的变化趋势和数值大小基本吻合。粒径分布参数D_(V50)与激光粒度仪测量结果的相对误差小于8%,其粒径分布满足燃煤电厂成品石灰石浆液的细度要求。

温室番茄水-沼液一体化的非充分灌溉模式评价

为探求温室番茄合理的水-沼液一体化非充分灌溉模式,于2021年3-7月和9-12月在甘肃省兰州市七里河区温室开展两季试验研究。应用水-沼液一体化穴灌技术在番茄3个生育期(苗期、开花坐果期和果实成熟期)设置高水低肥(充分灌溉)、中水中肥(轻度亏缺)、低水高肥(中度亏缺)3个水-沼液一体化非充分灌溉施肥水平,分析不同处理对番茄产量、灌溉水利用效率及品质的影响。构建了番茄综合品质递阶层次结构模型,并运用近似理想解(TOPSIS法)得到番茄综合品质评价值。同时,将番茄的产量、灌溉水利用效率、综合品质作为番茄综合效益的评价指标,应用组合评价法获得不同处理下番茄综合效益评价值。结果表明:T8处理(3个生育阶段均采用中水中肥)番茄单株产量最高为5.612 kg(2021年春)和5.032 kg(2021年秋);T9处理(3个生育阶段均采用低水高肥)番茄灌溉水利用效率最优为0.173 kg/L(2021年春)和0.171 kg/L(2021年秋);T8处理的番茄果形比、糖酸比、可溶性固形物、维生素C、可溶性蛋白质、果实含水率均为最高,番茄可溶性糖、可滴定酸和硬度最大值分别出现在T9、T4(苗期采用中水中肥,开花坐果期采用加低水高肥、果实成熟期采用高水低肥)和T3(苗期采用中水中肥、开花坐果期采用高水低肥、果实成熟期采用低水高肥)处理;两季试验中番茄综合品质评价和综合效益结果最好的均为T8处理。

以富CO_(2)吸收液为汲取液的沼液中水正渗透回收特性研究

针对沼气工程存在的沼液量大难处理问题及沼气提纯的需求,提出将正渗透技术与沼气CO_(2)化学吸收分离耦合,探究了沼气CO_(2)化学吸收中的富CO_(2)吸收液作为正渗透汲取液从沼液中回收水及浓缩沼液的可行性,并以沼液浓缩过程中的水通量、沼液浓缩倍数、沼液氨氮截留率与吸收剂反向传质通量为指标,考察了汲取液种类、汲取液浓度与其他操作参数对正渗透水回收性能的影响。结果表明,富CO_(2)吸收液作为汲取液从沼液中回收水并浓缩沼液具有可行性,且随着汲取液浓度、流量和温度的增加,沼液中水向汲取液的传质通量增加,沼液浓缩倍数也相应增加,但沼液中氨氮截留率下降,同时汲取液中的吸收剂溶质向沼液的反向传质通量也增加。当采用浓度2.5mol/L、CO_(2)负荷0.5mol/mol的富CO_(2)甘氨酸钾溶液作为汲取液,汲取液温度为70℃、流速为150mL/min、沼液室温及流速为150mL/min时,采用正渗透技术从沼液中回收水的初始通量达8.05L/(m^(2)·h),经过4h运行后,沼液浓缩倍数为1.18,氨氮截留率为84.13%,反向吸收剂通量仅为2.94g/(m^(2)·h)。

磁铁矿矿浆的矿石质量流量检测新技术

针对选矿过程中强磁性磁铁矿矿浆所包含矿石质量流量难以检测的问题,在分析现有主要检测技术的基础上,结合应用现场流程的特点,创新性提出一种单流量-双浓度的矿浆质量流量检测法,通过检测流程加水的流量以及加水前后矿浆浓度的变化,实现对强磁性磁铁矿矿浆所包含矿石质量流量进行精确检测。实际应用表明:该方法具有检测精度高、适应性强、稳定性好等特点,特别适用于含有磁铁矿的矿浆。

某石英砂浮选降铁工艺及机理研究

对某石英砂沉降脱泥洗矿后浮选除铁工艺进行研究,考察调浆酸种类、矿浆pH值、调浆时间、捕收剂用量、浮选矿浆浓度等条件对石英砂精矿中铁含量的影响。结果表明:捕收剂采用十二烷基磺酸钠(SDS)反浮选脱除该石英砂中赤铁矿可以达到降铁的目的;浮选降铁较优的工艺条件为,石英砂原矿经脱泥后分级,106~450μm粒级的石英砂入浮,盐酸调节矿浆pH值至3、调浆时间2 min、浮选矿浆浓度20%、捕收剂SDS用量400 g/t、起泡剂松油醇用量25 g/t。最终可获得SiO2含量达98.84%、Fe2O3含量仅0.022%的石英砂精矿,满足无色玻璃工业的入料要求。此外,通过动电位测试发现,矿浆pH值约为3时处于石英和赤铁矿的等电点中间位置,此时捕收剂阴离子会选择性地作用于赤铁矿表面,从机理上初步解释了该pH值条件下赤铁矿得到较好脱除的原因。

金属矿山充填浓度多目标优化控制

针对常规PID控制时充填浓度存在滞后性、时变性等特点,且易受尾砂性质和粒径等因素影响,提出了一种充填浓度的多目标优化控制策略。通过对充填工艺流程进行分析,构建充填浓度的多目标控制模型,设定多目标决策变量,建立对应的目标函数和约束条件,从底流浓度、充填质量、充填成本方面对充填浓度进行多目标优化,采用遗传算法进行求解,并在MATLAB中进行仿真。通过仿真曲线可知,多目标优化算法在评价指标方面满足质量合格、低成本的控制需求,与传统PID控制算法相比,多目标优化控制算法响应速度更快,鲁棒性更强,该充填系统运行以来,充填浓度稳定在70%±1%左右,成本降低15%,满足工业生产要求。

多釜连续溶解加料计算模型用于调控醋酸纤维素浆液固形分浓度

建立了多釜连续溶解加料计算模型,用于测算不同生产条件对醋酸纤维素浆液固形分浓度的影响程度,并进一步通过在实际生产过程中的运行监测,表明在进入溶解釜之前掌握醋酸纤维素和回收浆液等主要原料的关键指标后,通过模型可预测目标浆液固形分浓度的变化,从而通过调整相应参数后有效稳定浆液固形分浓度,确保丝束总旦的稳定。

研山铁矿选矿厂尾矿絮凝沉降试验及实践

研山铁矿选矿厂为了提高尾矿浓缩大井溢流水水质,针对当前尾矿浓缩大井存在的给矿量大导致溢流水浑浊、环水泵池清淤周期短等问题,开展了尾矿絮凝沉降试验研究。试验结果表明:在絮凝剂用量相同的条件下,随着矿浆浓度的升高,矿浆中固体颗粒的沉降速度随之变慢,澄清液变浑浊,结合现场实际生产情况,确定浓缩大井给矿浓度为8%;在矿浆给矿浓度为8%的条件下,当絮凝剂用量为8~10 g/t时,尾矿絮凝沉降效果较好,同时澄清液澄清,絮凝剂用量较原来降低50%,环水泵池清淤周期延长,周边环境卫生得到有效改善,同时大幅减少了人力、物力,年可创造经济效益约900万元。

矿浆电解法炼锑的工业实践

高砷锑金精矿的湿法处理是目前锑行业内普遍存在的问题,矿浆电解技术是一种有效且工艺流程短的处理方法,并有相应的工业应用。文章综述了高砷锑金精矿矿浆电解反应原理,介绍了工业试验的现状,以及试验运行中存在的问题和在产业化推进过程中需要改进的建议。

尾砂充填用高速搅拌机的研制与试验

针对现有充填料浆搅拌设备制浆不均匀、拆装检修耗时长、磨损快、使用寿命短等问题,开发研制出GSJ-100型尾砂充填料高速搅拌机。搅拌机内腔布置双层8根搅拌杆,对充填料浆进行充分剪切与碰撞,制得的充填料浆浓度高、均匀性好;圆筒形机壳采用两侧端盖密封,实现了不拆机生产线上进行维护和检修,提高了生产效率;针对搅拌杆、转子部件等易磨损件进行耐磨设计,大幅提高了设备的使用寿命;各零部件接触部位采用密封设计,保证了设备工作过程中不漏浆,密封效果好。工业试验结果表明,采用该搅拌设备制得的充填料浆或试块的强度、流动性和均匀性均能较好地满足充填设计指标,具有较广泛的应用前景。

月亮田煤矿选煤厂煤泥浓缩技术改造及应用

月亮田煤矿选煤厂为解决煤泥水系统指标不稳定、介耗高等问题,对现有煤泥浓缩系统进行了改造,将原有ITT70型斜管浓缩机替换为高效深锥浓缩机,同时优化加药方式;将中矸磁尾通过扫选浓缩后再进行磁选,提高了介质回收率。改造后有效解决了煤泥浓缩效果不佳、循环水质差、介耗高等问题,煤泥水浓缩净化效果得到了改善,生产循环水水质得到了明显提升,提高了综合经济效益。

浅析自动在线检测在选矿厂中的应用

对选矿过程的工艺参数进行在线检测,是实现生产过程控制和管理自动化的基础。矿浆浓度是选矿流程中重要的判断依据和参考指标,在选矿流程的磨矿、浮选、脱水等作业中,及时准确测量矿浆浓度对磨矿和浮选等一系列作业有着至关重要的意义。传统的测量方法,效率低下,不能实时监测浓度数据,无法适应自动化、智能化生产。为了建设智慧矿山,矿浆浓度的检测也就显得非常重要。