Performance Evaluation of Low-Carbon and Clean Transformation of China’s Coal Economy

In China,the oversupply of coal occurred in 2009,and from that year onwards,China’s coal economy began a low-carbon and clean transformation.Evaluating transformation performance is the research goal of this paper.The data collection for this paper includes data on deep processing of Chinese coal products from 2009 to 2020,as well as data on asset structure evolution and financial performance of 34 listed companies in the Chinese coal mining.Entropy value method is used to calculate the entropy value of low-carbon transformation,and the regression analysis is used to study the performance of cleaner transformation,the conclusion is as follows:(1)From 2009 to 2020,in China’s total energy consumption,coal consumption accounted for 71.6%in 2009 and 56.8%in 2020,the goals set by the state have been achieved.(2)The national goal of reducing the proportion of coal consumption and reducing carbon emissions has forced the transformation of deep processing of coal products.The transformation of coal enterprises towards low-carbon and clean production has achieved remarkable results.(3)From 2009 to 2020,the non coal industry income of 34 listed companies in China’s coal mining industry increased by 8.21%annually.At the same time,the asset structure was adjusted,and nearly 80%of the asset structure evolution showed an orderly development trend.(4)The regression analysis results show that the entropy value of coal deep processing products and the entropy value of asset structure adjustment are significantly related to transformation performance.The paper proposes to summarize the successful experience of China’s coal energy economic transformation,lay a foundation for achieving the carbon peak and carbon neutral goals in the future,further increase the intensity of coal deep processing,increase the proportion of clean energy in total energy consumption,and strive to control asset operation towards the goal of increasing the proportion of non coal industry income.

Clean Processing and Utilization of Coal Energy

The dominant status of coal on the energy production and consumption structure of China will not be changed in the middle period of this century. To realize highly efficient utilization of coal,low pollution and low cost are great and impendent tasks. These difficult problems can be almost resolved through establishing large-scale pithead power stations using two-stage highly efficient dry coal-cleaning system before coal burning,which is a highly efficient,clean and economical strategy considering the current energy and environmental status of China. All these will be discussed in detail in this paper.

The influence of intensity and properties of tectonic stress on the process of coalification

Through the research on stress metamorphism character of the II1 coal seam in Ludian gliding structure, the stress effecting factors of metamorphism and hydrocarbon generation process of tectonic coal were studied. It is shown that different tectonic stress has different coal evolution effects. Compared with tensional stress, compressive stress, which has apparent anisotropic characteristics, has greater stimulative effect against the increase of coal metamorphic degree, the abscission of functional group and side chains of basic structural unit, and the formation of gas primarily composed of methane.

Thermal recovery process of a backfilled open-pit in permafrost area at the Gulian strip coal mine in Northeast China

Timely and proper backfilling of open-pits in strip coal-mines has been an effective measurement for the recovery of the hydrothermal regimes and ecological environment in permafrost regions. In this study, numerical simulations and statistical regressions were applied for analyzing the recovery processes of the backfill and its major influencing factors for the thermal equilibrium in recently backfilled open pits at the Gulian strip coalmine in Mo'he, Northeast China. Results show that the thermal recovery time of backfilled areas is positively correlated to the backfill depth(BD) of the soils, the backfilled soil temperature(BST), and the mean annual ground surface temperature(MAGST); meanwhile, climate warming can impact on thermal regimes of the backfill area. The impact of climate warming on ground temperature of the backfill will show up significantly in about 50 years afterbackfilling(BD at 10.0 and 20.0 m, BST at 20.0°C) under the climate warming scenario(CWS) of 0.025°C·year ^(-1). Grey-relation analyses show that the sensitivity of the backfill recovery time declines in the order of the BD, BST and MAGST. On the basis of the abovementioned studies, the layer-by-layer backfilling in cold seasons is advised for more effective and more rapid recovery of thermal regimes of the backfilled open-pits in cold regions.

中国露天煤矿70年成就回顾及高质量发展架构体系

露天煤矿作为我国煤炭工业的重要组成部分,具有生产能力大、开采成本低、安全条件好等优势,近年来在建设规模、生产总量、开采工艺及技术装备等多方面均取得了跨越式的发展,有力保障了煤炭作为国家能源安全稳定供应的“压舱石”地位。首先回顾了新中国成立后我国露天煤矿70年来的发展历程,将其划分为起步恢复阶段(1949—1979年)、快速发展阶段(1980—1999年)、综合发展阶段(2000—2020年)和智能化初级发展阶段(2021年以后)4个时期;系统总结了每个时期的产量与数量规模、开采理论与技术、开采工艺与装备、资源开发与环境保护方面取得的突出成就。然后,探讨了现阶段露天煤矿发展面临的4个方面的主要问题,包括发展布局不均衡、可持续发展面临瓶颈、关键技术难题需深入攻关、人才短缺培养机制不完善。最后,提出构建以“安全、高效、绿色、低碳、智能”为总体目标的全链条、全周期、全要素露天煤矿高质量发展架构体系,其内涵特征包括以时效边坡理论、开采扰动指数理论、绿色开采理论、生态型开采理论、零碳负碳开采理论、智能化开采理论6种学术思想为理论基础,以灾害安全监测防控、复杂条件协同保障、生态源头减损开采、节能减污清洁利用、数字-自动-智能同建5类技术体系为核心支撑,以透明地质模型动态重构、边坡蠕滑全程精准预测、深大孔低扰动控制爆破、采空区超前探测与处置、粉尘抑制及煤自燃防治等30项关键技术为重点突破,以设计理念先进化、安全保障标准化、建设规模大型化、生产工艺综合化、开采装备智能化、核心制造国产化、矿区生态绿色化、煤炭利用清洁化、组织管理科学化、人才队伍国际化的“十化型”露天矿山为建设任务;同时给出了以规划引领为基础,以科技创新为驱动,以人才培育为保障的露天煤矿高质量发展实现路径。最终为推动我国露天煤矿向持续健康高质量方向发展提供指导。

Characteristics of coal sludge slurry prepared by a wet-grinding process

Coal sludge slurry(CSS) is an alternative fuel and a potential competitive method for sludge reduction.Based on the researches of coal water slurry, we studied CSSs by using a wet-grinding process with different types of regional municipal sludge(sludge) in an orthogonal experiment. The sludge type,sludge mixing proportion, dosage of dispersant, and grinding time were tested in this study. The results show that water content and its occurrence characteristics in the sludge have primary hindering influences on slurry ability. The range of fixed-viscosity concentrations with raw wet sludge is from 50.78%to 44.40%(by weight), while the range is from 53.35% to 51.51%(by weight) with dry sludge. All of the CSSs exhibit shear-thinning behaviors with different variation trends, especially the CSSs with more than 15%(by weight) raw wet sludge in it. Adding the same proportion of raw wet sludge increases the thixotropic properties of CSSs and the highest area of thixotropy loop is 3065 Pa/s, while the highest value of dry sludge is 1798 Pa/s. Hydrophilic group plays an important role in adsorbing water and building three-dimension networks with other particles, which is the main reason for CSS properties.Therefore, the mechanism can be used to find the way for making high quality CSS.

Coal waste management practices in the USA:an overview

This paper provides an overview of coal waste management practices with two case studies and an estimate of management cost in 2010 US dollars.Processing of as-mined coal typically results in considerable amount of coarse and fine coal processing wastes because of in-seam and out-of-seam dilution mining.Processing plant clean coal recovery values run typically 50%-80%.Trace metals and sulfur may be present in waste materials that may result in leachate water with corrosive characteristics.Water discharges may require special measures such as liner and collection systems,and treatment to neutralize acid drainage and/or water quality for trace elements.The potential for variations in coal waste production and quality depends upon mining or processing,plus the long-term methods of waste placement.The changes in waste generation rates and engineering properties of the coal waste during the life of the facility must be considered.Safe,economical and environmentally acceptable management of coal waste involves consideration of geology,soil and rock mechanics,hydrology,hydraulics,geochemistry,soil science,agronomy and environmental sciences.These support all aspects of the regulatory environment including the design and construction of earth and rock embankments and dams,as well as a wide variety of waste disposal structures.Development of impoundments is critical and require considerations of typical water-impounding dams and additional requirements of coal waste disposal impoundments.The primary purpose of a coal waste disposal facility is to dispose of unusable waste materials from mining.However,at some sites coal waste impoundments serve to provide water storage capacity for processing and flood attenuation.

煤矸石自燃的关键影响因素及治理方法研究现状

煤矸石作为煤炭的伴生产物,长期堆存过程中自燃现象频发,直接或间接产生生态污染、水体污染、地质灾害等诸多问题,造成巨大经济损失和人员伤亡。煤矸石从堆积初期到燃烧状态受诸多因素影响,包括自身性质、自燃条件和外部环境等,是一个复杂的物理化学反应过程。为提高煤矿矿区矸石自燃的防治能力,分析了煤矸石自燃理论的研究现状,系统总结了现阶段国内外学者对煤矸石自燃机理和治理方法的研究进展。围绕可燃物、氧气、温度3个影响煤矸石自燃的必要因素,提出了引发自燃的主要关键影响因素和作用过程机理。较全面介绍已有煤矸石山自燃防治的主要方法,对比分析了各种常规煤矸石自燃灭火手段以及治理技术的优缺点,指出了常规简单技术治理效果的局限性。针对煤矸石作为砂、石等替代材料,回填露天矿坑、采煤塌陷区等区域进行土地整治和生态修复,提出在防治过程中要明确自燃治理的控制对象,提升防灭火材料的特定性能,通过智能化设备提高辨识准确性进行精细化监控,并运用多种监测预警技术协同自燃防治材料多手段多方法运用综合治理,并提出了煤矸石自燃防治技术的未来发展和矿用防灭火材料的研究方向,为后续开展煤矸石自燃机理研究及自燃防治工程应用提供参考和理论支持。

贵州化处矿区煤炭地下气化物理模拟试验

为了深入探究贵州六枝化处矿区贫煤气化工艺参数,稳步推进贵州煤炭地下气化工程示范,开展了系列地下气化物理模拟试验和理论分析。通过构建综合模型系统,模拟了不同氧气浓度、气化炉结构和煤层湿度等条件下的气化过程,系统地探究了贫煤地下气化的特性、气化效率和气化工艺参数等。试验结果表明,气化炉结构差异对合成气组分有显著影响,同时,气化通道的支护方式、气化剂浓度、煤层含水量也会影响合成气组分。在适当的氧气浓度下,贵州六枝化处地区的贫煤能够稳定气化产出合成气,70%以下富氧环境下,随着氧气浓度的增加,煤气有效组分逐渐提高,煤气热值也相应增加;超过70%富氧时,有效组分中CO含量开始下降;温度场方面,气化过程的推进会直接影响温度场推移方向,且在煤层中会存在高低温区交叉分布的特征,主要是由于煤层中煤块之间存在裂隙,形成绕流燃烧而引起的。后期实际生产中,要控制气化剂氧气浓度,提高气化效率;钻井底部加强支护,采取热胀冷缩保护;增加辅助措施维持气化炉内温度场稳定性;为了提高H_(2)、CO组分浓度,需注入雾化水,增加还原性。通过深入探究不同工艺参数条件下贵州化处矿区贫煤地下气化特性,为下一步实际生产中气化工艺参数优化、气化效率提高和煤气质量提升提供了科学数据支撑。

贵州贫煤煤炭地下气化工艺参数研究

为推动煤炭地下气化(UCG)产业化发展进程,揭示高变质烟煤UCG工艺过程中物料转化的整体规律和影响因素,以贵州贫煤为例,系统探讨了不同气化剂配比下气化工艺参数的变化。通过收集梳理研究区资料,分析目标煤层煤质及煤热解动力学参数,并基于物料平衡与能量守恒理论基础,构建了物料平衡模型,对贫煤UCG工艺的参数进行了数值模拟分析,结果表明:研究区贫煤在N2气氛下热解DTG峰值温度为417.2℃,且随升温速率增加而升高,煤样的总失重率则随之降低;注水条件下,气化剂中氧气浓度的升高能够促进煤的气化反应,提高气化效率和合成气产品质量;但当氧气浓度超过80%时,煤气热值与CO的增长趋势会逐渐放缓;在纯氧-水气化工艺条件下,合成气产品有效组分达到65%,高热值为9.135MJ/m^(3)。相关成果可为贵州UCG产业化推进提供参考。

MO捕收剂对煤气化细渣浮选性能的影响

这是一篇矿物加工工程领域的文章。煤气化细渣的综合利用是现阶段的一大发展方向。煤气化细渣孔隙发达且含氧基团丰富,使得煤油等传统捕收剂难以回收其中的残炭。将油酸甲酯和煤油复配得到的药剂MO进行浮选实验,并通过激光粒度仪、红外光谱分析、接触角分析、XPS分峰拟合等手段进行机理探讨。结果表明,当MO药剂用量提高到16 kg/t时,尾矿烧失量降低到7.12%,可燃体回收率超过95.63%。MO药剂引入了极性基团酯基,其可以降低煤油表面的界面张力,增强捕收剂在水中的分散作用,从而增加残炭颗粒与捕收剂液滴的接触面积与碰撞概率,进而提高残炭颗粒的疏水性和可浮性。通过接触角分析不同药剂作用下残炭表面的疏水性,解释其与精矿产率的关系。通过XPS分析说明,MO与残炭表面的含氧官能团作用,能够在残炭的亲水位点形成有效的覆盖层,使得疏水部分朝外,降低了水化作用,增加了接触概率,增加该煤气化细渣的表面疏水性。MO药剂的使用为煤气化固体废弃物的综合利用提供了一种新途径。

低浓度含氧煤层气净化控制系统设计

低浓度含氧煤层气直接含氧液化精馏制液化天然气(LNG),在充分利用低浓度煤层气的同时又避免了煤矿瓦斯气直接排放造成的大气污染。首先,分析了含氧煤层气制LNG工艺中净化工段的工艺流程,结合工艺要求设计了可靠的控制系统。然后,根据低浓度含氧煤层气净化控制的工艺要求和系统规模,构建了分布式控制系统(DCS)的总体架构。在此基础上进行了硬件系统功能的选型及配置,以及对DCS软件的组态设计。最后,实现了DCS在工程实例中的一体化应用。该系统的应用提高了生产效率和产品质量,为工艺流程的稳定运行提供了安全保障。

乡村振兴背景下农村居民共同富裕统计测度及其分解——以宿州市为例

缩小地区之间和地区内部居民之间收入差距是中国实现共同富裕目标的重要议题之一。基于共同富裕内涵,构建了用于识别农村居民家庭共同富裕的多维指标体系,并在此基础上设计了各个指标的测度方法,以宿州市为例进行了实证检验。研究结果表明:乡村振兴战略实施以后,农村常住居民的生活条件和环境得到了极大改善,但是老弱病残幼成为农村常住居民的主要群体,劳动力水平、劳动力的健康状况、儿童就读学校成为农村居民实现共同富裕的重要影响因素。

稀缺主焦煤高效重介分选工艺在吕家坨矿选煤厂的应用

针对吕家坨矿选煤厂原生产工艺存在的问题,分析了入选原煤煤质特性,采用超宽粒级原煤三产品重介质旋流器选煤工艺、新型煤泥重介质旋流器选煤技术-反分流分选工艺、粗精煤泥两段弧形筛组合脱泥回收技术进行技术改造。改造后工艺系统指标检测结果表明,改造可提高综合精煤产率1.78%,增加税前利润10573.2万元。

基于改进ORB的复杂场景煤矸石匹配算法

在煤矸石分拣过程中,传统方法通过视觉识别与胶带速度预测煤矸石实时位姿,然而,由于煤矸石随胶带高速长距离运输过程中常发生打滑和跑偏现象,预测位姿与分拣区域实际位姿不一致,导致机械臂空抓、误抓,影响分拣效率。针对这一问题,提出了一种改进的ORB匹配算法用于煤矸石在分拣区域的二次定位,首先引入局部自适应伽马校正的oFAST特征检测,提高低光照下的匹配准确率;此外,针对矸石在高速移动中由于动态干扰产生的较多误匹配点,结合BEBLID描述子和GMS算法进行快速特征匹配,并运用随机抽样一致性算法优化匹配点选择,增强算法鲁棒性;最终,通过得到的匹配点计算最小外接矩形完成位姿获取。实验结果显示,所提算法相较于传统ORB算法在尺度、光照、视角变化下煤矸石匹配正确率分别提升了16.7%、36%和22%,平均误差为1.29 mm,平均匹配耗时在40 ms以内,适用于复杂场景下煤矸石的匹配定位。

基于机器视觉的煤矸石识别方法综述

煤矸石识别是煤炭智能化产业中的重要环节,而基于机器视觉的煤矸石识别技术是当前的研究重点和热点,但现有技术存在着一些问题和不足。首先揭示了外界因素对煤矸石图像采集的影响,其次阐述了煤矸石图像处理中的常用方法并指出了各方法存在的不足之处,最后总结了当前基于机器学习的煤矸石相关识别分类技术。基于上述研究成果,提出了当前煤矸石机器视觉识别方法的进一步研究方向,即:构建高质量的煤矸石数据集、研究高效的图像分割方法、选择最具代表性的煤矸石特征、优化深度学习网络模型结构。

煤矿井下钻探数字化监测系统

针对煤矿井下钻探存在孔底工程参数测量困难、钻探数据准确性和完整性不足、钻探数据融合应用不够等问题,设计了一种煤矿井下钻探数字化监测系统。该系统由数据来源层、虚拟模型层、数据处理层和钻探服务层构成:数据来源层为虚拟模型层提供数据支撑,虚拟模型层通过仿真模拟分析生成新的数据并反馈至数据来源层;数据处理层接收到数据来源层和虚拟模型层提供的数据后,进行数据清洗、转换及合并等处理;钻探服务层通过后台数据管理端的权限设置,为不同层级用户提供数据显示、查询、分析、报警等服务。将钻探数据按时序特征分为事前数据(钻探施工之前根据钻孔设计资料和施工方案等获取的数据)、实时数据(包括钻探过程设备实时监测的参数和钻场视频等)和延时数据(孔底随钻测量装置采集的参数),针对这3类钻探数据设计了数据处理流程,并建立了由接入层、汇聚层和核心层组成的系统通信网络架构。工程实践结果表明:该系统实现了煤矿井下钻探施工数据的采集、传输、显示与动态管理,满足钻探施工过程监测和数据管理的需求,具有较好的实时性和准确性。该系统为煤矿井下钻探智能化施工和精细化管理提供了技术支撑。

井下煤矸智能分选在新庄煤矿的应用

井下煤矸智能分选系统作为煤炭绿色开采的重要内容,能促使煤矿矸石不出井、地面无留存、有效杜绝矸石山地面堆放引发的系列生态环保问题,最大限度减少煤炭开采对生态环境的扰动。开展井下矸石智能分选系统建设是新型煤炭工业发展的方向,是构建人与自然和谐共生的新型能源供给体系的优先选项,设计推荐井下煤矸分选采用以智能干选机为核心的智能分选工艺。在井底煤仓下口布置TDS智能分选硐室系统。以减少矸石无效运输,提高原煤质量,节省运输成本,提高销售收入,提高企业经济效益。

选煤厂重介质分选工艺智能化改造及应用

针对陕西某选煤厂入选煤质变化较大、集成化不高、智能化程度底等问题,结合煤炭行业智能化应用与发展趋势,通过对选煤工艺流程和洗选装备进行分析,以自动化为基础,准确拾取底层数据,建立生产模型,主要针对重介系统、浓缩系统等环节进行改造,提高了选煤厂生产的科学性和稳定性,实现了降本增效、安全生产。

Modeling of fine coal flotation separation based on particle characteristics and hydrodynamic conditions

Flotation is a complex multifaceted process that is widely used for the separation of finely ground minerals. The theory of froth flotation is complex and is not completely understood. This fact has been brought many monitoring challenges in a coal processing plant. To solve those challenges, it is important to understand the effect of different parameters on the fine particle separation, and control flotation performance for a particular system. This study is going to indicate the effect of various parameters （particle Characteristics and hydrodynamic conditions） on coal flotation responses （flotation rate constant and recovery） by different modeling techniques. A comprehensive coal flotation database was prepared for the statistical and soft computing methods. Statistical factors were used for variable selections. Results were in a good agreement with recent theoretical flotation investigations. Computational models accurately can estimate flotation rate constant and coal recovery （correlation coefficient 0.85, and 0.99, respectively）. According to the results, it can be concluded that the soft computing models can overcome the complexity of process and be used as an expert system to control, and optimize parameters of coal flotation process.