scholarly journals Conical picks of mining machines with increased utility properties – selected construction and technological aspects

2021 ◽  
pp. 195-204
Keyword(s):  
Underground Mines ◽  
Hard Coal ◽  
Working Process ◽  
Conical Pick ◽  
Cutting Machine ◽  
Wear And Tear ◽  
Rock Mining ◽  
Symmetrical Body ◽  
Conical Picks ◽  
Mechanical Mining

Shearers and roadheaders are commonly used to extract useful mineral deposits, especially hard coal, and for drilling roadways in underground mines, tunnels and other underground buildings in civil engineering. As the primary working process of this type of machines, mechanical mining of rocks is carried out by cutting. These machines' working units are equipped for this purpose with picks, usually conical (point-attack). They have the form of an axially symmetrical body consisting of a steel shaft and a tip usually made of tungsten carbide, connected by a hard brass solder. Due to the possibility of spontaneous rotation in the pick holders and even wear and tear of their tip around the entire perimeter, conical picks have a much longer service life compared to radial picks. Their life, especially when cutting hard and sharp abrasive rocks, is, however, still unsatisfactory. Rapid wear of the picks leads to a decrease in mining efficiency, an increase in this process's energy consumption, and an increase in dynamic surplus to which the cutting machine is subject. Among many forms of wear and tear of the conical picks, attention was paid to the problem of asymmetrical abrasive wear of the tips, pulling out the connection of the soldered pick tip and fatigue breaking of the pick shafts in the transition zone of the shank into the shoulder. The article presents original propositions of modification of the construction of the roadheaders/shearers conical pick shafts and the method of fixing the tip in the pick shaft in order to increase their operational durability significantly. The technologies and devices necessary to manufacture conical picks of the proposed structure were described. The developed modifications significantly contribute to the improvement of functional properties, including the reliability of conical picks, used in particular for hard rock mining.

scholarly journals Conical Pick Production Process

2020 ◽  
Vol 3 (1) ◽  
pp. 231-240
Author(s):  
Łukasz Bołoz ◽  
Antoni Kalukiewicz ◽  
Greg Galecki ◽  
Liubomyr Romanyshyn ◽  
Taras Romanyshyn ◽  
...  
Keyword(s):  
Large Scale ◽  
Rapid Development ◽  
Scale Production ◽  
Opencast Mining ◽  
Market Demand ◽  
Conical Pick ◽  
Construction Methods ◽  
Rock Mining ◽  
Conical Picks ◽  
Materials Used

AbstractOne of the basic methods of mechanical rock mining is cutting, which faces increasingly difficult working conditions. Despite the rapid development of machines used in underground and opencast mining as well as in tunnel building, construction industry and road engineering, the problem of insufficient durability of mining tools remains unsolved. In addition to drilling and, to a lesser extent, planing, cutting provides a huge market for tools. Currently, the process of cutting is mainly based on conical picks. The cutterheads of cutting machines are equipped with several dozen, and frequently – more than one hundred conical picks, which, due to their workability and abrasiveness, sometimes work only a few hours. There is a market demand for over two hundred models of conical picks. This is due to the huge variety of shapes and sizes of picks as well as the methods of their mounting in the holder. The article briefly presents various solutions of conical picks, their construction, methods of protection, dimensions and materials used. Next, based on materials produced by ZWM Carbonex, the classic method of their manufacture using the turning technology has been described. The authors have also presented briefly the use of die forging for the large-scale production of picks, applied by Górnicza Fabryka Narzędzi Sp. z o.o.

scholarly journals Methods of Mechanical Mining of Compact-Rock—A Comparison of Efficiency and Energy Consumption

Energies ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3562
Author(s):  
Kotwica ◽  
Małkowski
Keyword(s):  
Energy Consumption ◽  
Rock Type ◽  
Final Part ◽  
Mechanical Method ◽  
Rock Types ◽  
Mechanical Methods ◽  
Rock Mining ◽  
Mechanical Mining ◽  
Compact Rock

This paper compares the methods of mechanical mining of rock in terms of their efficiency, energy consumption, and the durability of the tools they involve. It presents the advantages of mechanical heading-driving methods. In the first part, we described the methods used to assess rock workability, and the influence of rock types and parameters on mining efficiency. Furthermore, we discussed the compact-rock mining process in terms of the energy it consumes. We provided the description of the most common mechanical methods, such as milling, static crumpling and undercutting, including the tools involved, and the requirements and limitations for the use of these methods. The paper presents unique machinery solutions designed to reduce the energy consumed by mining processes. In the final part of the paper, we propose a solution to select the mechanical method of rock mining as a function of rock type and parameters.

scholarly journals Experiment on Conical Pick Cutting Rock Material Assisted with Front and Rear Water Jet

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Xiaohui Liu ◽  
Songyong Liu ◽  
Lie Li ◽  
Xinxia Cui
Keyword(s):  
Cutting Tools ◽  
Rock Breaking ◽  
Water Jet ◽  
Break Rock ◽  
Conical Pick ◽  
Advantages And Disadvantages ◽  
Pressure Water ◽  
Quantitative Results ◽  
Conical Picks ◽  
High Pressure Water Jet

Conical picks are one kind of cutting tools widely used in engineering machinery. In the process of rock breaking, the conical pick bears great cutting force and wear. To solve the problem, a new method, conical pick assisted with high pressure water jet, could break rock effectively, and four different configuration modes of water jet were presented. In this paper, based on the analysis of the different water jet configuration’s advantages and disadvantages, experiments on front water jet, new typed rear water jet, and the combination of those two water jet configuration modes were conducted to study the assisting cutting performance and obtain the quantitative results.

scholarly journals Coordinate Transformation Using the Author’s Software in GIS Class System – Case Study

2021 ◽  
Vol 20 ◽  
pp. 7-19
Author(s):  
Violetta Sokoła-Szewioła ◽  
Marian Poniewiera ◽  
Aleksandra Mierzejowska
Keyword(s):  
Spatial Data ◽  
Underground Mines ◽  
Hard Coal ◽  
The European Union ◽  
Hard Coal Mining ◽  
Uniform Manner ◽  
The Stability ◽  
Different Sources ◽  
Selection Of

In order to implement the provisions of the INSPIRE Directive, it is necessary for the Member States of the European Union to take appropriate measures to enable combining in a uniform manner spatial data deriving from different sources and sharing use of them by many users and many applications. Spatial data regarding underground hard coal mining in Poland should also be available in the national spatial reference system. Mining enterprises run a cartographic resource in the different rectangular flat coordinate systems. The standard transformation procedure does not provide the required accuracy because these are areas affected by mining activity, and the stability of points is limited, hence, studies were undertaken. The result is the development of software that can be used in Geographic Information Systems to transform spatial data from a system used in mine to the national system. The article described shortly a chosen coordinates systems used in Polish underground mines, elaborated procedure for selection of the degree and the type of a transformation polynomial in the transformation task. It presents its practical application of procedure for the area of one of hard coal mines using the author’s software elaborated in the results of above-mentioned research.

scholarly journals Groundwater Chemistry and Stratification in the Flooded Hard-Coal Mine Shaft “Nowy I” (Nowa Ruda Region, SW Poland)

Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3257
Author(s):  
Krzysztof Chudy ◽  
Magdalena Worsa-Kozak ◽  
Agnieszka Wójcik
Keyword(s):  
Isotope Analysis ◽  
Groundwater Chemistry ◽  
Underground Mines ◽  
Hard Coal ◽  
Depth Range ◽  
Mine Shaft ◽  
Rock Formations ◽  
Chemical Composition Of Water ◽  
Groundwater Samples ◽  
Mine Flooding

The flooding of unprofitable underground mines is one of the methods of their closure. After the drainage of the mine has stopped, the voids left in the rock mass as a result of mining, are filled with inflowing groundwater. In this way, reservoirs of groundwater with specific physicochemical parameters are formed. These parameters depend on the interaction of the water flowing into the workings with the rock formations. It was the economic situation in the 1990s that led to the closure of hard coal mines in the Nowa Ruda Coal Basin, where the flooded “Nowy I” shaft is located. In that shaft, in 2008, hydrogeological research was performed and groundwater samples from five various depths were collected. The aim of the study was to recognize if groundwater stratification occurs in the shaft. In 2015, a sample of the water outflowing through the “Aleksander” adit was taken to check the potential influence of mine flooding on the environment and to confirm the changes in groundwater chemistry over time. These were the first, and so far, the only studies on the chemical composition of water in the flooded mine in that area. The article presents results of the preliminary research, which confirmed the existence of not obvious hydrogeochemical stratification in the shaft. It can be assumed that below the depth of 350 m, the water circulating through mining excavations exhibits the highest electrical conductivity and the highest concentration of Ca2+, K+, SO42−, Fetot. In the depth range of 320–380 m there is a transition zone, in which a decrease of Eh value and a change of reduction and oxidation is recorded. Above this zone, infiltration water inflow, from outside the shaft casing, dominates. The research shows that it would be necessary to perform additional sampling of the water in the shaft at greater depths, as well as to perform isotope analysis and periodical tests for at least several years. This would allow for a more complete characterisation of hydrogeochemical processes taking place in the flooded mine.

Mathematical model of site-maker for the formation sites around the stumps

10.12737/8465 ◽  
2015 ◽  
Vol 4 (4) ◽  
pp. 147-155
Author(s):  
Поздняков ◽  
Evgeniy Pozdnyakov
Keyword(s):  
Mathematical Model ◽  
Ground Level ◽  
System Of Equations ◽  
Cutting Machine ◽  
Flexible Working ◽  
Wear And Tear ◽  
Below Ground ◽  
Machine Elements ◽  
Working Bodies

Technological process and design of site-maker is proposed with flexible working bodies in the form of rope pieces, performing remote of the soil by sites around stumps for their grinding below ground level in order to improve the quality of tillers on cutting and efficiency of the cutting machine elements to reduce the stumps by reducing wear and tear resulting from their contact with soil particles. A mathematical model of site-maker is developed, system of equations describing the device as a whole and interaction of the elements of flexible working bodies, soil and stump one another are presented.

scholarly journals New Computer Simulation Procedure of Heading Face Mining Process with Transverse Cutting Heads for Roadheader Automation

2017 ◽  
Vol 62 (1) ◽  
pp. 83-104 ◽  
Author(s):  
Marian Dolipski ◽  
Piotr Cheluszka ◽  
Piotr Sobota ◽  
Eryk Remiorz
Keyword(s):  
Underground Mining ◽  
Rock Cutting ◽  
Operating Conditions ◽  
Cutting Process ◽  
Experimental Investigations ◽  
Technical Parameters ◽  
Rock Mining ◽  
Conical Picks ◽  
Actual Shape ◽  
Cutting Path

Abstract The key working process carried out by roadheaders is rock mining. For this reason, the mathematical modelling of the mining process is underlying the prediction of a dynamic load on the main components of a roadheader, the prediction of power demand for rock cutting with given properties or the prediction of energy consumption of this process. The theoretical and experimental investigations conducted point out – especially in relation to the technical parameters of roadheaders used these days in underground mining and their operating conditions – that the mathematical models of the process employed to date have many limitations, and in many cases the results obtained using such models deviate largely from the reality. This is due to the fact that certain factors strongly influencing cutting process progress have not been considered at the modelling stage, or have been approached in an oversimplified fashion. The article presents a new model of a rock cutting process using conical picks of cutting heads of boom-type roadheaders. An important novelty with respect to the models applied to date is, firstly, that the actual shape of cuts has been modelled with such shape resulting from the geometry of the currently used conical picks, and, secondly, variations in the depth of cuts in the cutting path of individual picks have been considered with such variations resulting from the picks’ kinematics during the advancement of transverse cutting heads parallel to the floor surface. The work presents examples of simulation results for mining with a roadheader’s transverse head equipped with 80 conical picks and compares them with the outcomes obtained using the existing model.

scholarly journals Establishment of Coal-rock Constitutive Models for Numerical Simulation of Coal-rock Cutting by Conical Picks

2019 ◽  
Author(s):  
Shuo Qiao ◽  
Jingyi Xia ◽  
Yimin Xia ◽  
Zaizheng Liu ◽  
Jinshu Liu ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Constitutive Model ◽  
Total Error ◽  
Rock Cutting ◽  
Maximum Deviation ◽  
Uniaxial Compression Test ◽  
Conical Pick ◽  
Simulation And Experiment ◽  
Coal Rock ◽  
Conical Picks

One of the key points in numerical simulation of coal-rock cutting by conical picks is to select a proper coal-rock constitutive model. In order to find a reasonable coal-rock constitutive model, a uniaxial compression test was conducted to obtain the constitutive model. The several stages for linear elastic deformation and creep, plastic yielding, hardening, and finally brittle cracking of the constitutive units were studied, and the coal-rock constitutive model was established. As a result, the coal-rock cutting by one conical pick or two conical picks was simulated and the results were compared with coal-rock cutting experiment on a Coal-rock Cutting Machine. According to the simulation and experimental results, it is believed that the numerical simulation can reveal coal-rock crushing process. And the total error rate of coal-rock cutting by one conical pick between the simulation and experiment is 8.5%. The maximum deviation of coal-rock cutting by two conical picks between the simulation and experiment is 9.8%. All simulation values are within a reasonable range. The comparison indicates that the coal-rock constitutive model should better be defined considering the coal-rock crushing process by conical picks.

scholarly journals Results of a Study on the Quality of Conical Picks for Public Procurement Purposes

2018 ◽  
Vol 1 (1) ◽  
pp. 687-693
Author(s):  
Łukasz Bołoz
Keyword(s):  
Public Procurement ◽  
Underground Mines ◽  
Operating Costs ◽  
Road Engineering ◽  
The Public ◽  
Material Parameters ◽  
Conical Picks ◽  
Optimum Price ◽  
Selection Of

Abstract The article presents the results of a study on the quality of conical picks for the purposes of tender procedures in accordance with the public procurement law in Poland. The pick studies presented here are one of the few that in practice allow the selection of an offer based on objectively determined numerical indicators defining the quality of the product and not only on the basis of price. Thanks to this, the contracting party can decide the relevance of price and quality in their evaluation of a pick. The geometrical and material parameters required in a tender, if not met, are the basis for rejecting a given offer of picks. The numerical parameter influencing the final evaluation of the offer is the picks’ rate of wear. Conical picks are tools for mining minerals, rocks, asphalt or concrete. They are used in many industries, especially in mining, construction and road engineering. In difficult working conditions, the durability of knives is limited to as little as several hours. Several dozen picks work on a cutting unit at the same time, and taking into account the price of a knife which oscillates around several dozen euros, significant operating costs are incurred. Therefore, the selection of tools with an optimum price-quality ratio is crucial. The article presents the results of studies on geometric parameters, material parameters and the rate of wear of 48 sets of picks conducted for a tender consisting of 14 tasks. The tender was conducted for 6 underground mines of a coal company. Five producers submitted their offers for selected tasks in the tender.

An experimental study on wearing of conical picks interacting with rock

2019 ◽  
Vol 43 (4) ◽  
pp. 544-550 ◽  
Author(s):  
Qiuxia Fan ◽  
Qianqian Zhang ◽  
Guirong Liu ◽  
Xin Li ◽  
Wei Jia ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Numerical Models ◽  
Wear Resistant Coating ◽  
Mining Machine ◽  
Conical Pick ◽  
Wear Resistant ◽  
Resistant Coating ◽  
Two Factors ◽  
Conical Picks ◽  
Rotary Cutting

Wearing of conical picks on a coal mining machine and roadheaders are investigated experimentally using a full-scale rotary cutting machine. This study considers three types of conical picks with different tip materials to examine the effects of wear resistance of conical picks and wear characteristics in response to cutting load. The influence of pick wear on the cutting load and pick tip temperature are analyzed, thereby providing an experimental-based guideline for reducing pick wear. The results indicate that the cemented carbide pick has the best wear resistance among the three kinds of picks studied, and the pick life can be significantly extended for picks with a wear-resistant coating surface. It is also found that pick wear has the greatest influence on the normal force. Thermal fatigue and overloading are two factors that cause pick wear failure. The results can also be used to design the conical pick with wear-resistant coating and to validate the numerical models.

Sign in / Sign up

Export Citation Format

Share Document