Category Archives: bulk solids handling Archive

High Size Reduction Ratios: Cage Mill Working Principles and Performance Factors

By E. Marcotte Cage Mills are internally fed impactors that can crush, grind or pulverize many different materials to specified degrees of fineness. They are characterized by a high ratio of size reduction after a single pass through the cages and easy maintenance. Continue reading High Size Reduction Ratios: Cage Mill Working Principles and Performance Factors

A descriptive Explanation of the Belt Tracking Properties of Pulleys by using the geometric Properties of the flat Pattern of their Surface

By G.A. Kribitz The direction of a conveyor belt is changed, at pulleys, according to the wrap angle between the pulley and the belt. Compared with idler rollers which just support a conveyor belt, pulleys, due to the wrapping belt, provide different opportunities concerning belt tracking. Due to relatively high belt tensions and wrap angles combined with the according friction factors, pulleys mainly provide static friction to the conveyor belt at the ongoing side [1]. There are different hypotheses available in literature for the explanation of belt tracking and belt misalignment effects concerning pulleys, but apparently none seems to be accepted to be generally valid. Continue reading A descriptive Explanation of the Belt Tracking Properties of Pulleys by using the geometric Properties of the flat Pattern of their Surface

Creating Value from Overburden: Valuable Rock Grade obtained from Contaminated Feed Material

By R. Schmid The new dry process clay adhesions from screen waste produced in quarries and gravel pits. Operators report that they are able to convert more than 90 % of contaminated feed material into salable rock grade using the ‘Combimix’ system. Continue reading Creating Value from Overburden: Valuable Rock Grade obtained from Contaminated Feed Material

Powerful and Mobile: Giant mobile Dust Control Design delivers extended Coverage

The new trailer-mounted dust control system by Dust Control Technology features a throw range of 100 meters and the ability to deliver 140,000 square feet (15,500 square meters) of coverage area. Continue reading Powerful and Mobile: Giant mobile Dust Control Design delivers extended Coverage

Stochastic Models for Gravity Flow: Numerical Considerations

By W.H. Gibson Material flow analysis is commonly required in mining methods were the rock has to move from its initial position to the extraction point, commonly known as gravity flow. This happens in mining methods such as sublevel caving, panel caving, block caving. During this process the ore is diluted with waste from the walls of the cave column or waste sitting on top of the ore. It is essential for the mining design to assess the degree of dilution for different draw strategies to minimise the waste extraction and optimise the ore recovery. Stochastic methods have proved to be a good alternative for this type of assessment and might also be interesting for for the description of the movement of materials in (big) silos. Continue reading Stochastic Models for Gravity Flow: Numerical Considerations

Unproper Belt Scale Results? 10 Reasons, why your perfect Belt Scale might under-perform

By M. Morrissey Belt weighing is common practice in lots of bulk solid handling operations. Although it’s a long established technology, there are still bits and pieces regarding installation and maintenance which might lead to erroneous results. Following you can find the reasons why. Continue reading Unproper Belt Scale Results? 10 Reasons, why your perfect Belt Scale might under-perform

Feeding of Biomass: Design Experience with Wood Chips

By M. Rackl, Yuan Tan, W.A. Günthner Part of the international struggle to reduce the carbon footprint in energy consumption is the utilisation of biomass instead of fossil fuels such as coal or oil. Although the basic approach is quite promising, as there is a huge amount of usable biomass, there are some problems to be solved with regard to its application due to the largely differing form of appearance of the various base materials. In the following, some research into storage and handling of different wood products including DEM measures are presented. Continue reading Feeding of Biomass: Design Experience with Wood Chips

Reliable Energy Supply: Efficient Conveying, Storage and Dosing of alternative Fuels for Cement and Lime Plants

By A. Eichelmeyer – Cement manufacturing is particularly energy-intensive. In order to reduce the use of expensive primary fuels like coal and oil, cement plant operators focus increasingly on Alternative Fuels and Raw materials (AFR).  Continue reading Reliable Energy Supply: Efficient Conveying, Storage and Dosing of alternative Fuels for Cement and Lime Plants

Parameters affecting Power Consumption in Pneumatic Conveying of Fine Particles

By N. Behera, V.K. Agarwal, M.G. Jones, K.C. Williams – Pneumatic conveying of certain bulk materials is widely used in industries due to certain advantages over other modes of conveying. As compared to dilute phase, dense phase conveying is a preferred method of conveying due to its low power consumption, low erosive wear and low attrition of particles. Fly ash and alumina being high aeration capable due to their fine particle size tend to be conveyed in fluidised dense mode at low velocities. In this paper, details of pneumatic conveying tests are presented which are carried out using fly ash and alumina as conveying material at different solids loading ratios for dense mode as well as dilute mode of flow. Continue reading Parameters affecting Power Consumption in Pneumatic Conveying of Fine Particles

The Proper Flow Rate – Material Feed Rate Control for Pneumatic Conveying Systems

By D. Mills, V. Agarwal The material feeding device is particularly critical to the successful operation of any pneumatic conveying system. Many of the feeders available have no moving parts and it is not always obvious how material flow rate can be reliably achieved. Continue reading The Proper Flow Rate – Material Feed Rate Control for Pneumatic Conveying Systems