非规则采矿工作面积分区间确定方法

针对工作面形状多种多样的特点 ,本文采用二次曲线描述工作面水平投影边界 ,并且利用分段积分的方法处理更加复杂的工作面形状 ,合理地解决了非规则采矿工作面积分区间的划分问题 ;同时 ,给出了工作面形状系数的计算公式 ,整个计算过程利用计算机技术实现自动解算 ,避免了对任意曲边形工作面采用矩形分割的近似处理方法 ,提高了地面沉陷预计精度。最后 ,用实例说明了本文提供的对非规则采矿工作面的处理方法比现行处理方法具有更高的精度。

宜阳矿采矿工作面由纵采改为横采的实践

通过对采场工作面开采方法的改进 ,实施贫富兼采 ,合理配矿 。

浅谈复杂通风条件的采矿工作面通防安全问题研究

本文以复杂通风条件的采矿工作面通防安全管理工作现状为切入点,展开具体分析,并以此为依据,提出合理安装安全检测监管系统、优化通防安全管理体系、运用先进技术优化通防设计结构等几方面重要举措。通风安全问题是复杂通风条件下采矿工作面安全安全管理工作中的一项关键问题,正确开展通防安全管理工作,是保证采矿工作面施工人员人身安全的必然要求。

石灰石矿山采矿工作面最优长度的确定

介绍了影响采矿工作面长度确定的各种要素 ,分析了传统的利用电铲生产能力确定工作面长度的弊端 ,阐述了采用计算公式确定工作面长度的技术优势。

风煤钻松帮卸压在采掘工作面巷道中的应用

"三软"不稳定煤层松软围岩条件下的巷道支护,一直是困绕义马煤业集团铁生沟煤矿的支护难题。文章在总结多年经验的基础上,针对松软围岩条件下巷道压力大、两帮鼓出、底鼓严重,造成支架变形、巷道失修、断面缩小等情况的治理,提出一些可借鉴的方法。

放顶煤工作面端头"弧三角形悬板"的弹性分析

放顶煤采煤工作面端头是顶板事故的多发地,其主要影响因素是"弧三角形悬板"的运动方式与稳定范围,它影响着工作面端头项板的稳定和支护的难易程度。通过弹性分析可知,分层厚度的大小直接影响着"弧三角形悬板"尺寸的大小。在现有的采掘技术条件下,可以把分层厚度小的、不稳定的顶板通过对岩层的锚固,变为厚度大的、稳定的顶板,使之形成大小适度、完整稳定的"弧三角形悬板",从而改善工作面端头顶板及超前支护的现状。

开采技术因素对露采矿石损失与贫化的影响

开采技术因素对露天采矿过程中矿石损失、贫化有较大的影响。运用图解分析法对损失率、贫化率的计算公式进行了推导 ,并就采矿工作面的推进方式、矿岩接触处分爆线位置、矿岩分爆面倾角等开采技术因素对矿石损失。

矿山建设中安全施工问题及对策分析

针对矿山建设中安全施工问题,提出了解决方案,分析巷道曲率半径、施工面等风险要素,在此基础上,研究针对性对策,解决了矿山检测与采矿中的安全隐患。通过对采矿工作面进行优化、根据现场实际设计巷道,控制具体爆破条件与技术参数,实现了矿山建设中的安全管理目标。

新型气体间隔装置在矿山爆破中的应用

我公司石灰石矿山共有3个采矿工作面,炸药库储量较小,最大允许贮药量为2t,每次炸药采购量只能在1.8t左右,造成炸药供应量不足;同时矿山离居民区距离较近,最近的工作面离居民区仅450m,爆破产生的震动给居民生活和建筑物安全带来影响。

枣园煤业自制输送机气动分煤装置

河南永锦能源有限公司枣园煤业成功研制出胶带输送机气动分煤装置。该煤业主皮带煤流系统运输能力大，采矿工作面出煤时，煤转载到地面高架走廊皮带后，由于其运输能力有限，不选择分煤时，容易造成高架走廊皮带压死现象，进而造成电机烧毁，并影响生产。对此，该矿技术人员利用气缸升降原理，在高架走廊皮带机尾上部安装了一个气动分煤装置，根据煤量大小调节分煤装置高度，控制了高架走廊皮带运输能力，有效避免了皮带压死现象，且减轻了维修人员的劳动强度，提高了效率。

Study on the change rule of groundwater level and its impacts on vegetation at arid mining area

The shallow groundwater in Shendong mining area was broken because of large-scale underground mining activities. Selecting 32201 working-face as research area, analyzed the change rule of groundwater level and aquifer thickness under mining impact with a large number of water level observation data. Then, the impacts of groundwater level change on vegetation were analyzed by the relationship theory of arid area groundwater and vegetation. The results show that the aquifer structure and the water condition of supply flow and drainage are changed by the water proof mining. The groundwater level recovere only a little compared with the original groundwater level in two years. But the great change of groundwater level do not have notable influences on vegetation of this mining area, and further study indicates that there are certain conditions where groundwater level change impacted on vegetation. When the influence of groundwater level change was evaluated, the plant ecological water level, warning water level and spatial distribution character of original groundwater and mining-impacted groundwater-level change should be integrated.

Study on gob-side entry retaining technique with roadside packing in longwall top-coal caving technology

Pointed out some technical difficulties of gob-side entry retaining with roadside packing in longwall top-coal caving technology (LTCT), and analyzed the function mecha-nism of roadside filling body. Theory analysis shows the mechanical properties of high water material fit for the feature of deformation of gob-side entry retaining in LTCT, and gob-side entry retaining in LTCT face is one of effective ways to increase the recovery ra-tio of mining district.

Roadway deformation during riding mining in soft rock

"Riding mining" is a form of mining where the working face is located above the roadway and advances parallel to it.Riding mining in deep soft rock creates a particular set of problems in the roadway that include high stresses,large deformations,and support difficulties.Herein we describe a study of the rock deformation mechanism of a roadway as observed during riding mining in deep soft rock.Theoretical analysis,numerical simulations,and on site monitoring were used to examine this problem.The stress in the rock and the visco-elastic behavior of the rock are considered.Real time data,recorded over a period of 240 days,were taken from a 750 transportation roadway.Stress distributions in the rock surrounding the roadway were studied by comparing simulations to observations from the mine.The rock stress shows dynamic behavior as the working face advances.The pressure increases and then drops after peaking as the face advances.Both elastic and plastic deformation of the surrounding rock occurs.Plastic deformation provides a mechanism by which stress in the rock relaxes due to material flow.A way to rehabilitate the roadway is suggested that will help ensure mine safety.

Characteristics of compression fracture of ＂three soft＂ coal bed by perfusion and gas sucking technique

Against the particularity of stratum-structure in ＂three soft＂ mine areas, according to rock indoor test and on-site sucking experiment, discussed the characteristics of argillization, compression fracture and sucking technique of soft coal with low permeability. It is clearly pointed out that the gas can be highly effectively sucked only by compression fracture along the occurrence of the coal seam, creating inter-seams crack belt because of the difference of bulgy deformation. After the flooding experiment in the 24080 workface of Pingdingshan No. 10 mine, the average single-bore volume of gas increases from 77 m3 to 7 893 mS, while decay cycle extended from 7 days to 80-90 days. Also, the single-bore extracting rate of gas increases to 33%.

Gradient principle of horizontal stress inducing rock burst in coal mine

Based on the stress distribution characteristics of rock burst multiple sites, the criterion of horizontal stress inducing layer dislocation rock burst was established. Accordingly, the influencing factors were analyzed. The analysis results indicate that the stress condition, edge of etastic zone depth, supporting strength, and the friction angle and cohesion among coal stratum, roof and floor are sensitive factors. By introducing double-couple model, the layer dislocation rock burst was explained and the energy radiation characteristics were analyzed. The SOS micro-seismic monitoring system was applied to observe the rock burst hazards about a mining face. The results show that P- and S-wave energy radiations produced by rock burst have directional characteristics. The energy radiation characteristics of the 22 rock bursts occurring on 79Z6 long-wall face are basically the same as theoretical results, that is, the ratio of S-wave energy of sensor 4 to 6 is about 1.5 and that of P-wave is smaller than 0.5. The consistency of the monitored characteristics of the energy radiation theoretically increases with the total energy increasing.

CO emission in the air return corner of the working face in shallow burial mining areas

In shallow burial mining areas, abnormal CO emission and the spontaneous combustion of coal are great threats to safety production at a fully-mechanised working face. In order to prevent the CO concentration in the air return corner from exceeding the critical limit, the paper studied the CO emission regularity and characteristics through theoretical analysis, experimental research and field observation. The results show that the main sources of CO emission were the spontaneous combustion of coal in the goaf and the exhaust emissions coming from underground motorised vehicles. The effect factors of CO emission were also investigated, such as seasonal climate changes, the advancing distance and advancing speed of the working face, the number of underground motorised vehicles and some other factors. In addition to these basic analyses, the influence mechanism of each influence factor was also summarised theoretically. Finally, this study researched the distribution and change law of CO concentration in the fully-mechanised working face in two aspects: controlling the change of monitoring points and time respectively. The research results provide a theoretical basis for preventing the CO concentration from exceeding the critical limit in the air return corner and reducing the possibility of spontaneous combustion of coal. Additionally, the results also provide important theoretical and practical guidelines for protecting miners' health in modern mines featuring high production and high efficiency all over the world.

Maximal loads acting on legs of powered roof support unit in longwalls with bumping hazards

In the article the results of measurements of the resultant force in the legs of a powered roof support unit, caused by a dynamic interaction of the rock mass, are discussed. The measurements have been taken in the longwalls mined with a roof fall, characterized by the highest degree of bumping hazard. It has been stated that the maximal force in the legs F m, recorded during a dynamic interaction of the rock mass, is proportional to the initial static force in the legs F st,p . Therefore a need for a careful selection of the initial load of the powered roof support, according to the local mining and geological conditions, results from such a statement. Setting the legs with the supporting load exceeding the indispensable value for keeping the direct roof solids in balance, deteriorating the operational parameters of a longwall system also has a disadvantageous influence on the value of the force in the legs and the rate of its increase, caused by a dynamic interaction of the rock mass. A correct selection of the initial load causes a decrease in the intensity of a dynamic interaction of the rock mass on powered roof supports, which also has an advantageous influence on their life. Simultaneously with the measurements of the resultant force in the legs, the vertical acceleration of the canopy was also recorded. It has enabled to prove that the external dynamic forces may act on the unit both from the roof as well as from the floor. The changes of the force in the legs caused by dynamic phenomena intrinsically created in the roof and changes of the force in the legs caused by blasting explosives in the roof of the working, have been analyzed separately. It has been stated that an increase in the loads of legs, caused by intrinsic phenomena is significantly higher than a force increase in the legs caused by blasting. It means that powered roof supports, to be operated in the workings, where the bumping hazard occurs, will also transmit the loads acting on a unit during blasting. The majority of recorded force changes in the legs has been caused by a dynamic interaction of the roof. They are characterized by a load increase coefficient K d, satisfying the inequality 1 06<K d =F m /F st,p <1 24. A much smaller number of cases, when the external load acted on the bases, was recorded. Individual, recorded results of measurements indicate that changes of the force in the legs, caused by external loads of this type, run more intensively due to roof loads (1 08< K d<1 80),particularly in these cases when the near the roof layer of the seam is under mining. A determination of more precise relations among the changes of forces in the legs, caused by a dynamic interaction of the floor and the bases and the mining and geological conditions requires a performance of additional underground tests.

Carbon monoxide adsorptive capability of low rank coal's maceral

The centrifugal separation with gravity experiment was made for getting every pure macerals like inertinite and vitrinite,and the isothermal adsorption tests of pure mac- eral are carried out at 30,40,50,55,60,65℃,respectively,after analyzing the proximate element and maceral of coal samples,which was aimed to study the CO adsorptive capa- bility of every maceral of low rank coal at difference temperature and pressure.The results show that the adsorption isotherm of CO can be described by Langmuir equation because it belongs to the Type I adsorption isotherm at low temperature(T≤50℃),and the tem- perature effect on coal adsorption is greater than of pressure in lower temperature and pressure area;what's more,the relationship is linear between the coal adsorption quantity of CO and the pressure at high temperature(T>50℃),it can be described by Henry equation(Q=KP),which increases with pressure.Both temperature and pressure has great influence on CO adsorptive capability of low rank coals,especially the temperature's effect is so very complex that the mechanism need to study further.At the same time,the volatile matter,inertinite,oxygen-function groups and negative functional groups are high popu- larly in low rank coal samples,especially,the content of hydroxide(-OH) has great influ- ence on CO adsorption in that the inertinite has stronger effect than vitrinite on adsorptive capability of low rank coal samples,the result is same to the research on CH4 adsorption.