Jaw Crusher Research Articles

On the Possibility of Using Manganese Carbonate Ores in Ferromanganese Industry

The problem of energy consumption in the ferroalloy industry has become an enormous challenge as the cost of energy permanently increases, while the reserves of good-quality raw materials are decreasing. Hence, the valorization of low-quality raw materials becomes necessary under the conditions of keeping the quality of products within the marketable range and low energy consumption. From the history of smelting of manganese alloys, it is known that the priority was always given to high-grade manganese-oxide ores because the quality of the ore has a great influence on numerous important parameters. This was mainly connected with the pyro metallurgical advantages offered by high-grade ores, including high manganese content (minimizing the materials consumption), lower power consumption caused by its oxide nature, and high fusibility. However, in the last 50 years, the ferroalloy industry faces the problem of application of the carbonate ores with an aim to compensate the depletion of the reserves of oxide manganese ores and meet the requirements of steelmaking in which manganese alloys find their primary use. In the present work, we study two manganese ores, namely, pure oxide and carbonate ores. A jones riffle was used for sample preparation. A jaw crusher and zip mill were used to decrease the size of particles, a graphite crucible was used as the container of the ore, and an induction furnace was used for smelting. Various proportions of oxides and carbonates manganese ore were mixed and smelted at 1550°C in the argon atmosphere for 1 h. The investigations of the ores and products were carried out by using the x-ray diffraction (XRD) method, an ICP-OES spectrometer, and a scanning electron microscope with energy dispersive spectrometer. It was shown that a marketable high-carbon ferromanganese can be produced with at least 75% Mn and a slag containing less than 20% MnO. The results obtained for oxide-carbonate blends with 90–10%, 80–20%, 70–30%, 60–40%, and 50–50% ratios met market requirements. However, the results accumulated for oxide-carbonate blends with 20–80% and 0–100% ratios showed that the alloys obtained as a result of smelting contained only 48% Mn and 68% Mn, respectively, despite the fact that the slag contained ≤20% MnО.

Disintegration process modeling for a jaw crusher with complex jaws swing

Disintegration process modeling for a jaw crusher with complex jaws swing

Perancangan Sistem Daur Ulang Pasir Pada Industri Pengecoran Logam Skala Kecil Untuk Peningkatan Efisiensi Biaya Dan Pengurangan Limbah

Metal casting is a part of the manufacturing process to produce products that generally have intricate shapes or materials that can not be processed by ordinary machining. The complexity of the product can be achieved with the use of sand molds and the use of cores that are also made of sand. The process of recycling sand can be done by mechanical, thermal and chemical recycling methods. The sand system that has been used to produce waste in the form of waste sand, dust and other contaminants. This waste can be used for several purposes, among others: reused as metal casting sand, road construction, brick material etc. So far, recycling has been done on large scale metal casting. For medium and small scale this is not done. Used sand is treated as waste that is discarded and not utilized. The manufacture of a sand recycling system for metal casting allows the reuse of waste sand for print sand with the technical properties of sand that meet the desired quality. It will also be able to reduce waste disposed by metal casting. The study began with a literature study to find out the characteristics of used sand. Next is to plan the recycling process of the former sand, which then continued with manual sand recycling experiment. Against the recycled sand is then tested to determine its properties. The results of recycling experiments and test results are then analyzed to serve as a basis for designing and manufacturing sand recycling machines for small scale metal casting. The type of sand to be recycled is the CO2 process sand with a base of quartz sand. Based on the research that has been done, the following conclusions are obtained: CO2 process recycling sand technology produced is in the form of recycling system and analysis / study on the quality of recycling; design prototype sand recycling machine CO2 process produced is a design engine jaw crusher and hammer mill machine design.

Investigation on effects of different crushing stages on morphology of coarse and fine aggregates

ABSTRACTThe present study evaluates the effects of three different stages of crushing mechanism, namely two stage (2S), three stage (3S) and four stage (4S) on various morphology parameters (i.e. angularity, texture, flatness & elongation, sphericity and form2D) of aggregates. The 2S crushing consisted of primary and secondary crushers as Jaw and HSI (horizontal shaft impactor), respectively, while 3S crushing was composed of primary, secondary and tertiary crushers as Jaw, Jaw and HSI, respectively. In other word, 3S consisted of an additional jaw crusher compared to 2S crushing. Likewise, 4S crushing had primary, secondary, tertiary and quaternary crushers as Jaw, Jaw, HSI and VSI (vertical shaft impactor), respectively. The 4S had an additional VSI crusher to 3S crushing. Three coarse and three fine aggregate sizes were used in the study. A digital device, Aggregate Image Measurement System was used to measure various morphology parameters of aggregates and to assess the effects of stage crushing. The coarse aggregates were subjected to angularity, texture, sphericity and flatness and elongation, while fine aggregates were studied for angularity and form2D. A systematic statistical analysis was conducted to compare the mean value of aggregates shape parameters and draw logical conclusions. It was observed that effects of crushing on aggregate shape are a cumulative function of stage crushing, crushing mechanism and aggregate size. The outcome of the present study may be helpful in understanding effects of stage crushing mechanism on shape parameters of aggregates for quality production. Further, the study can assist in selection of an appropriate source of aggregate and crusher health monitoring via morphological characterisation of aggregates.

Revisiting gouging abrasion test for jaw crushers

Abstract The use of a gouging abrasion test to evaluate the wear of jaw crushers is revised in terms of its procedures, considering the effects of the most significant variables, such as the minimum amount of crushed material and the minimum opening between the jaws during the crushing cycle (minimum discharge aperture). A correlation between the work hardening of jaws and the amount of crushed material is presented. The wear of stationary and movable jaws is compared, being the results dependent on the jaw's material and the discharge aperture. The abrasiveness of several rocks was evaluated, showing a good correlation with their Mohs hardness.

Effect of Crusher Type and Crusher Discharge Setting On Washability Characteristics of Coal

Natural resources have been serving the life of many civilizations, among these coals are of prime importance. Coal is the most important and abundant fossil fuel in India. It accounts for 55% of the country’s energy need. Coal will continue as the mainstay fuel for power generation. Previous researches has been made about the coal feed size and coal type had great influence on the crushing performance of the same jaw crusher and amount of fines generated from a particular coal depends not only upon coal friability but also on crusher type. Therefore, it necessitates crushing and grinding the coal for downstream process. In this paper the effect of crusher type and crusher discharge setting on washability characteristics of same crushed non-coking coal has been studied. Thus four different crushers were investigated at variable parameters like discharge settings, different capacities and feed openings. The experimental work conducted for all crushers with same feed size and HGI (Hardgrove Grindability Index). Based on the investigation the results indicate that the four crushers which has been involved for the experimental work shows that the variation in not only the product size distribution and also reduction ratio. Maximum breakage has been occurred at coarsest size fraction of irrespective of crusher type and discharge setting.

The influence of stone crushing processes on aggregate shape properties

Aggregate shape properties have a direct influence on the behaviour of pavement materials. The crushing process is the main factor responsible for generating these shape properties; however, there has hardly been any effort directed toward optimising the performance of pavement materials by altering the crushing techniques to produce aggregate particles with desired shape properties. The aim of this research is to analyse how the crushing process influences aggregate shape properties. Form, angularity and surface texture of five coarse and five fine aggregates, from three different quarries, were evaluated by means of digital image processing and were categorised by two different classification systems. The jaw crusher produced coarse aggregates with a better combination of sphericity and angularity during the first crushing stage. Fine aggregates produced by cone crushers in the final crushing stages were more elongated, but had a greater angularity than fine aggregates produced by the primary jaw crusher.

The Behavior of FRA Concrete with High Replacement Ratio

This study deals with determination of the properties of the fine recycled aggregate (FRA) concrete with partial replacement of natural sand in concrete mixtures. The FRA was obtained from concrete waste and crushed on fraction 0 – 4 mm by laboratory jaw crusher. The geometrical and physical properties of natural sand and the FRA were tested. The main goal of this study is evaluation of the basic physical and mechanical properties of the concrete with partial natural sand replacement by the FRA such as workability, water absorption capacity, compressive strength and flexural strength. A total four concrete mixtures were prepared. The first concrete mixture was prepared only with natural sand, did not include the FRA. In other concrete mixtures, natural sand was replaced by the FRA in various replacement ratios (40 %, 50 %, and 60 %). All concrete mixtures were designated with the same parameters for clear comparison. The workability of fresh concrete mixtures and physical and mechanical properties of hardened concrete were tested.

Resource-Saving Quality Management Systems of Coal Products Using the DSKA-4m Сomplexes

The article presents developed and widely implemented processing technologies of mining enterprises (crushing, classification, averaging adjustment screen composition, dehydration, loading, storage, reducing the ash content and moisture source)-based complexes DSKA. Offers innovative technical software allows mining companies and companies to create and consumers, in accordance with fluctuations in the market, to adjust flows of products providing a wide range of quality. Coal crushing and classification equipment is widely used in coal mines, sea and river ports, railway terminals and large coalstorage yards. However, drawbacks of the conventional technologies used in crushing (jaw, cone, rotary and rolling crushers), sizing (on low-frequency high-amplitude screens) and conveying (belt conveyors) worsen efficiency of production and decrease its attractiveness as investment. Besides, the preparation plants in service cannot, as a rule, ensure the integrated and adjustment-flexible approach to providing the desired quality of coal end product.

A Vibrating Jaw Crusher with Auteresonant Electric Motor Drive of Swinging Movement

The article relates to a vibrating jaw crusher with pendulum vibrating exciter auteresonant electric motor drive and with elastic element rational force distribution, with limited peak-to-peak swing. Its design and its math model are presented. Also disclosed is the operating principle of a vibrating jaw crusher and the control algorithm for controlling the crushing jaw for maintaining the operating mode at resonant frequency.

МАТЕМАТИЧЕСКОЕ ОПИСАНИЕ ПРОЦЕССА ДРОБЛЕНИЯ В ЩЕКОВОЙ ДРОБИЛКЕ

МАТЕМАТИЧЕСКОЕ ОПИСАНИЕ ПРОЦЕССА ДРОБЛЕНИЯ В ЩЕКОВОЙ ДРОБИЛКЕ

Influence of Reclamation Process on the Ecological Quality of Reclaim Sand

Abstract In this article, there were presented results of research on influence of reclamation process on the ecological quality of reclaim sand with furan resin used in nonferrous foundry. The quality of reclaimed sand is mainly define by two group of chemical substances from elution of reclaimed sand: Dissolves Organic Carbon (DOC) and Total Dissolves Solids (TDS). Reclaimed sand used in test was prepared in experimental thermal reclaimer and mechanical vibration reclaimer REGMAS installed in Faculty of Foundry Engineering at University Of Science and Technology in Krakow. The reference point is molding sand shaking out and crumble in jaw crusher. Test of elution was made in accredited laboratory in Center For Research and Environmental Control in Katowice up to the standard with Dissolves Organic Carbon (DOC) - PN-EN 1484:1999; Total Dissolves Solids (TDS) - PN-EN 15216:2010. The standard for elution test is PN-EN 12457- 4:2006. Except that we were made loss of ignition test, to check how many resin was rest on sand grains.

Effects of compression and sliding on the wear and energy consumption in mineral crushing

The majority of the operating costs of commercial crushing are caused by the power consumption and the wear part maintenance. Better understanding of the variables affecting the compressive crushing is needed when aiming to lower the operational costs of material comminution. The gouging or high stress wear tests are commonly conducted with laboratory sized jaw or cone crushers that do not allow easy alteration of the movement or geometry of the wear surfaces. Therefore, a new innovative jaw crusher-type wear tester was designed especially for wear and mineral property research. The modular jaws of the developed dual pivoted jaw crusher allows flexible selection of jaw geometry, which is independent of the selectable compressive and sliding movements of the jaws. The narrow jaw design produces extensive wear in the specimens even when small amounts of abrasive are crushed. The reference tests with a structural steel show excellent repeatability of the wear loss and energy measurements during the tests. The results with varying sliding movement of the jaws showed linear dependency between the wear of the jaw plates and energy spent. A method to separate the energy spent in wear from the energy spent in comminution is also described in this paper.

Washability Study on El-Maghara Coal Mine Reject

Egypt is not a coal-rich country; however, El-Maghara coal seams in Sinai (52 million tons with about 27 million tons as minable reserves) is the only coal reserve. Due to the importance of coal as a source of energy, this work deals with an attempt to retrieve escaped coal (gangue) as much as possible using Sink-and-float technique. A bulk sample was collected from the waste dumps of El-Maghara coal mine. The results were characterized by measuring yield recovery and ash contents. Sample was prepared by successive stages of crushing through jaw and roll crushers. Crushed sample was introduced to the screening process using a set of screens (6, 4, 2, 1 and 0.5 mm). Organic liquids such as Bromoform (CHBr3), Carbontetrachloride (CCl4) and Gasoline with specific gravities of 2.6, 1.59 and 0.721 respectively were used. Several bathes of various specific gravities (1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9 and 2.0 g/cc) were prepared from organic liquids. The obtained results indicated that, we can achieve about 18.94% clean coal yield recovery with ash content of 2.58%, washing degree of 18.10 and separation efficiency of 95.53% respectively at heavy medium of 1.3 specific gravity. Also, the obtained results at 1.4 specific gravity were 19.78 % clean coal yield recovery with ash content of 2.61%, washing degree of 18.88 and separation efficiency of 95.47%.

The kinematics and mechanical advantage of the double-toggle jaw crusher

The purpose of this article is to obtain a comprehensive mathematical description of the kinematics of a double-toggle jaw crusher. The driving mechanism of the crusher is modeled as a planar six bar linkage. Two closed position vector loops that characterize the configuration of the mechanism are used to derive expressions for the angular position, velocity and acceleration of the moveable jaw. Dimensional data of a typical double-toggle jaw crusher are used in the derived mathematical expressions to demonstrate their application. Moreover, starting with the equation for the angular velocity ratio of the moveable jaw, with respect to the input crank, an expression for the ideal mechanical advantage of the crusher is derived. The expressions derived in this paper provide the foundation for further investigations into the mechanics and the design of the double-toggle jaw crusher.

Comparative Laboratory Studies of Conventional and Electrodynamic Fragmentation of an Industrial Mineral

In order to address comminution efficiency, which could be defined as the increase in mass specific surface against net specific energy input, the energy consumption of an industrial mineral with and without pre-weakening by high voltage pulses covering the same size range were compared. The three tested comminution sequences consisted of a laboratory jaw crusher or pilot scale high voltage pulse machine at two different circulating loads, a laboratory crusher and two tumbling mills of differing grinding media; all being operated following the principles of energy optimized comminution according to the OCS-method. The first results indicate that possible energy reduction by electrodynamic pre-weakening is available in the immediately subsequent, but not in further conventional comminution stages for the tested industrial mineral.

DESIGN AND OPERATIONS CHALLENGES OF A SINGLE TOGGLE JAW CRUSHER: A REVIEW

A review on the design and operations challenges of a single toggle jaw crusher is presented. Strength and fracture toughness of the material to be crushed are intrinsic properties that determine the time and energy required to crush the material. Economy of the crushing process is partly dependent on the angle of nip. Productivity of the crusher can be improved upon by increasing the eccentricity of the eccentric shaft, use of reversible jaws, bush bearing and easily adjustable toggle plate. Vibrations and fatigue cracks in the crusher frame will be nipped in the bud through structural analysis at design stage. Determination of the optimal angle of inclination of the toggle plate, development of jaws with varying wear rate along the crushing chamber, and development of comminution energy models that take into cognizance relevant crushing parameters for simulation and optimization of the crushing process are some areas that require close attention. Â http://dx.doi.org/10.4314/njt.v36i3.22

Parametrization procedure for jaw crusher tooth plates

Parametrization procedure for jaw crusher tooth plates

DESIGN AND OPERATIONS CHALLENGES OF A SINGLE TOGGLE JAW CRUSHER: A REVIEW

A review on the design and operations challenges of a single toggle jaw crusher is presented. Strength and fracture toughness of the material to be crushed are intrinsic properties that determine the time and energy required to crush the material. Economy of the crushing process is partly dependent on the angle of nip. Productivity of the crusher can be improved upon by increasing the eccentricity of the eccentric shaft, use of reversible jaws, bush bearing and easily adjustable toggle plate. Vibrations and fatigue cracks in the crusher frame will be nipped in the bud through structural analysis at design stage. Determination of the optimal angle of inclination of the toggle plate, development of jaws with varying wear rate along the crushing chamber, and development of comminution energy models that take into cognizance relevant crushing parameters for simulation and optimization of the crushing process are some areas that require close attention. http://dx.doi.org/10.4314/njt.v36i3.22

Improving the properties of recycled concrete aggregates by accelerated carbonation

Large amounts of construction and demolition wastes, especially concrete wastes, are generated annually. Until now, only a small fraction of concrete wastes has been reused as recycled concrete aggregates (RCA) in the manufacture of mortar and concrete. In order to optimise the use of RCA for new concrete, it is important to improve the properties of RCA. RCA are mainly composed of an intimate mix of natural aggregates and adherent hardened cement paste, which has a much larger porosity than natural aggregates. The influence of accelerated carbonation on the properties of RCA was studied in this work. Original concrete was manufactured and crushed by a jaw crusher in the laboratory. The different fractions of laboratory-produced RCA were stored in an accelerated carbonation room. The mass loss, density, porosity and water absorption of the RCA were tested before and after carbonation. Industrial RCA were also studied for comparison with the laboratory-produced RCA. The results clearly showed that, after accelerated carbonation, the density of the RCA increased due to the transformation of portlandite into calcite. The water absorption and porosity of the RCA decreased after carbonation.