types of thickeners in mineral processingbest stand for samsung rear speakers
In the process of thickening (also called sedimentation), the solids in a suspension settle under the influence of gravity in a tank and form a thick pulp. A multi-disciplinary CSIRO research team was recognised for their development of a comprehensive set of tools and techniques for improving the performance of gravity thickeners used by the minerals industry for large-scale separation of fine particles from process liquid. Thickeners are designed to operate continuously with slurry/water consistently flowing into the centerwell with thickener underflow pumping balanced to maintain a mud bed in the thickener. High-Rate Thickeners can be supplied with flat-bottom, on-ground tanks or elevated tanks, which feature short suction lines that reduce the risk of plugging. In comparison with filtration, thickening offers the advantage of low operation costs; on the other hand, it has the disadvantage of leaving a higher moisture content in the pulp. According to the number of working surfaces, it can be divided into single-layer, double-layer and multi-layer thickeners. Soil conditions and ground water elevation affect foundation design and may determine tank and mechanism type. A great number of dryer types are available. It is designed to translate horizontal feed momentum into a gentle vertical motion. Ordinary thickeners are the most commonly used thickener in concentrators. Our thickener is specifically designed for the mineral processing industry and tailing processing. We will send detailed technical information and quotation to you! This high-level of water recovery keeps water consumption at sustainable levels, as well as drastically reduces the slurry volume reporting to waste ponds. High-efficiency thickeners diameter can be reduced to 1/3-1/2 of that of ordinary thickeners. The LSG Series comprises a spur gear and pinion drive system with automatic raise and lowering of the rakes, specially designed to cope with uctuations in the feed solids. Please leave your message here! Increase the particle size of settling solid particles by adding flocculant , thus to accelerate the settling speed; The settlement distance is shorten and the settlement area is increased by the installation of inclined plate ; Play the role of flocculation, filtration, compression and increase the treatment capacity of the thick layer of mud deposition; Complete automatic control facilities are equipped. On larger units these rakes are braced to the arms with angles and tied by means of tie rods. They are ideal for sites where water is scarce or expensive. The information includes process models, animations and a searchable knowledge base that contains research data and comprehensive reviews on thickener technology. Essential elements common to thickeners include: a)Feedwell: where the slurry or water is introduced into the thickener which confines the kinetic energy of the incoming waters to minimize overall tank turbulence as well as directing the flow downward into the thickener, b)Rake mechanism: or similar device that pulls the settled solids/mud to the center of the tank; as the rakes travel through the mud, this plays an additional important role in disturbing the mud and releasing additional water retained by the settled mud. Get to Know Us. [Source: CSIRO], A thickener at WMC Resources' operation in Western Australia. Get more nice stuff in your inbox instantly by Subscribing to us. High-rate thickeners produce the lowest density and yield stress (<20 Pa). Inclined plate thickener is equipped with many inclined plates inclined to the center of the thickener on the upper part of the cylindrical pool of the ordinary thickener, these plates are along the circumference, and the angle with the horizontal is about 60. This thickening eect is achieved by rejecting the greater part of the water in a solids free condition, thus making it suitable for re-use in a closed circuit washing progress. In the following situations, it is better to use an ordinary thickener: Slurry without suitable flocculant. Ordinary thickeners, inclined plate thickeners and high-efficiency thickeners are all commonly used thickening equipmentin mineral processing plants. It can also be divided into peripheral drive thickener and central drive thickener accord the drive mode. 188, Xinhai Street, Fushan high-tech industrial development district, Yantai, Shandong, China. For some ore slurry, flocculants have no obvious economic benefits or are uneconomical at all, so we should use ordinary thickener. Mineral processing equipment and solutions by JXSC Mining Machinery. (Click to know3 common problems and solutions of mining thickeners). 3.High Efficiency ThickenerIn addition to the inclined plate installed in the thickener, the high efficiency thickener has a special flocculant adding mechanism. This at times required additional research skills and these were obtained through collaboration with other research groups from Curtin University of Technology, Murdoch University and the University of Melbourne. If you want to know more details about equipment, solutions, etc, please click the button below for free consultation, or leave your requirements! c)Under flow pump: which can be of several types including peristaltic, centrifugal, diaphragm and progressive cavity. McLanahan offers a range of thickener types, including High-Rate,Ultra Rakeless,High-DensityandPaste, that are tailored to an individual application. The diameter of the thickener can be reduced to 1 / 3-1 / 2 of that of the common thickener, and the floor area is only 1 / 9-1 / 4 of that of the common thickener. Coagulants are sometimes also used when fine particle recovery is a challenge with flocculants alone. Convection dryers, employing a flow of hot combustion gases to remove moisture from a pulp stream, are the most common. 2.Inclined Plate ThickenerThe inclined plate thickener is equipped with many inclined plates on the upper part of the cylinder tank of the common thickener. Keep current with leading edge industry news and Mainland Machinery updates. Achieving the appropriate velocity and shear conditions are critical to minimize the polymer consumption. A larger Thickener will generally require less operator attention. You folks are always on top of things. may require covered and/or insulated tanks with attendant seals. These plates accelerate the separation of ore particles, shorten the material settlement time, strengthen the separation and settlement process, improve the concentration efficiency, reduce the capital investment, and increase the production capacity by 3 times. These determine the. They can be used as stand-alone solutions or in conjunction with other equipment. These tanks, equipped with mechanical scraping devices and launders are usually termed thickeners in the metallurgical field and clarifiers in the sewage and water purification fields.Thickeners, equipped with the patented spiral scrapers and angle rakes are a distinct improvement over all types of mechanical raking devices now in use. Although the new high-efficiency thickener has the advantages of high processing capacity, less land occupation and low investment, it still cannot completely replace the ordinary thickener. They can also be used to reduce the size of settling ponds or tailings storage facilities. Where flocculant is optimally dosed is typically determined by plant evaluation and varies from operation to operation and is influenced by solids substrate, particle sizes and system specific factors. Settled solids at the bottom of the thickener is called mud. The amount of material larger than 250 micron (+60 mesh) in the feed. A lifting device is a mechanical attachment to the drive head that lifts the Thickener's entire rake mechanism out of the mud bed. Usually expressed as area per unit weight of dry solids per day. The simple animation below that shows only flocculant addition (not coagulant) illustrates these thickener operational principles. Concentrates and tailings produced by the methods outlined above must be dewatered in order to convert the pulps to a transportable state. If coagulants are used, typically these are dosed upsteam of the flocculant addition point; however, in mineral concentrates, most often the best response is dosing coagulant after the flocculant. Paste Thickeners feature tanks with high side walls and steep floor slopes to aid with the compression effects of the mud. Key information and technology from each of the projects is provided to all project sponsors in an interactive CD-Rom and through a website restricted to project sponsors. The above is according the physical structure to divide the thickener. It may also require a rake lifting device. The design is heavy-duty to deal with the rigorous of mineral processing. There are currently three types of thickeners commonly used in mineral processing plants: ordinary thickeners, inclined plate thickeners and high-efficiency thickeners. While not always necessary, a rake lift is commonly used to provide some insurance against bogging of a Thickener. For this reason, the dewatering of pulps containing fine particles often involves a combination of thickening and filtration. The role of thefeedwell in a Thickener is tomix the slurry feed and flocculant under the right shear conditions to promote the fastest free settling. Find your mining knowledge all in one place! Most McLanahan Thickeners (but not all) incorporate a low profile rake design with or without dewatering pickets, and the rake drive is powered either by a hydraulic power pack or direct coupled electro-mechanical gearbox. A rakeand picket system powered by a rugged drivehelps create dewatering channels in the mud bed, allowing further compaction of the mud. This pulp, and the clear liquid at the top of the tank, can be removed continuously or intermittently. The MEP Thickener Drive Mechanisms are centre drive types relying on the conventional basis of design which is a well made, heavy duty machine capable of handling arduous dues encountered in mineral processing industries. For instance, Thickeners can be used in locations where water is in short supply or very expensive, providing immediately reusable process water back to the plant. Introduction of Commonly Used Mining Thickeners, 3. The XL series provides a rotation only mechanism for less arduous dues where uctuaons in the feed rate to the Thickener can be handled by a variable speed underow pump. From a metallurgical point, the exclusive design of the Spiral Rake imparts a continuous turning motion which conveys the thickened pulp from the outside of the tank to the center cone. The high-efficiency thickener has a special flocculant addition mechanism in addition to the inclined plates in the round pool. Bill Hancock is an internationally recognized expert in mineral processing technologies, technical marketing management and water treatment. Precautions for Remolding the Thickener. Check Out What Were Doing in Prince Rupert. Since the high-efficiency thickener is suitable for the treatment of medium-concentration underflow, it should not be used when the underflow concentration is too high. CSIRO Medals 2004 - Business Excellence Medal, CSIRO Medals 1999 - Research Achievement Medal, Thickener technology for mineral processing, concentrate mineral slurries prior to extraction of commodities, create a liquid free of solids for subsequent extraction of dissolved metals, Award for excellence in innovation for CSIRO-led research (Achievement). Optional sensors for monitoring bed level, underflow density and overflow turbidity ensure optimal operation. Slurry temperature, vapors, gases, etc. It is a new type of high-efficiency thickener which is increasingly widely used. The more quickly this settled material is raked to the discharge cone, the less chance there is for overload. As the processing load is relatively large, try to consider installing devices that automatically raise the rake or adjust the speed. Thickeners are used by mineral and aggregate producers, as well as by environmental contractors in industries such as wastewater management, to separate solids from liquid in a slurry. When combined with other downstream processing equipment, such as a Filter Press, Thickeners can potentially eliminate settling ponds altogether. Source: This article is a reproduction of an excerpt of In the Public Domain documents held in 911Metallurgy Corps private library. Interesting artical. Please consult your localMcLanahan representativeto identify the most cost-effective option for your application. /wp-content/uploads/2021/07/forweba-300x99.png, Industrial Services: Helping Your Next Project Succeed, https://mainlandmachinery.com/wp-content/uploads/2017/01/Thickener-Operation.mp4, Dry Flocculant Mixing and Feeding Design Considerations, Accurate Slurry and Pulp Level Measurement. Thickener costs vary due to the wide range of duties and styles. Please pay attention to the following points during the remolding, In order to achieve the expected flocculation effect, the slurry concentration should be adjusted, not too thick or too thin. So you will get email everytime we post something new here. The overall strategy for the P266 projects has been to enhance full-scale thickener performance and downstream processes by developing a deep scientific understanding of the fundamental physicochemical processes. Additionally coagulants can have positive downstream operational benefits such as in filters. Our customer service team is here to help you 24/7. This type superstructure is usually carried on piers outside the tank rather than on the tank sides. Therefore, it becomes more widely used recently. Mining pedia is a professional blog whose posts are ALL ABOUT MINING. With the help of the slow-running (1/31/5r/min) harrow installed in the thickener, the thickened underflow slurry is discharged from the underflow port at the bottom of the thickener. 2022 MineralDressing.com and JXSC Mining Machinery Co., Ltd. All rights reserved. Large volumes of mineral suspensions are treated with speciality chemicals called flocculants, which induce the fine particles to aggregate and thereby settle more readily. The thickening of finely grained pulps is often aided by the use of flocculating agents. Units can also be manufactured to t a concrete tank provided by the customer. Flocculants are typically introduced either to the slurry-water pipe feeding the thickener, to a feed tank before the thickener, to the centerwell or a combination of these addition points. However, due to the larger diameter, its area is larger and the production capacity per unit area is lower. Mild steel shell walls mounted to a concrete base. These measures accelerate the separation of ore particles, shorten the settling time of materials, strengthen the separation and settling process, improve the concentration efficiency, reduce the capital investment, and increase the production capacity by about three times. In some industries, they are used as Clarifiers to remove minerals and fines from process water. This model has been designed to meet the demand for a rugged but simple and cost eecve unit. +44 (0)1722 744799 enquiri[emailprotected]. Froth control or removal may require sprays, froth baffles or skimmers. The rakes are fabricated of rolled steel sections, to the correct curvature to transport the material to the center. One or more rotating radial arms are there within the tank, from each of which are suspended a series of blades, shaped so as to rake the settled solids towards the central outlet. Watch How A Thickener Worksto see how the feedwell mixes and distributes the slurry particles. RV Investigator to arrive in Hobart tomorrow! Feed and underflow material settling characteristics that may require special rake construction such as blades located a distance below the rake arms on posts or spikes on the blades to cut into packed solids. The CSIRO team has become the world leader on gravity thickening science, which has been applied to a wide range of issues within thickeners operating across the full spectrum of the minerals industry, delivering benefits of at least A$400 million (NPV) being reported by end-users of the technology. Ability to produce non-Newtonian underflows. A wide variety of thickeners are used including conventional, deep well, paste, high rate and clarifiers which is a thickener subclass used for removing solids from turbid or very low % solids waters. The slurry should be degassed and defoamed, and the oil and other substances that affect sedimentation should be removed. Modern thickeners are designed based on use of highly effective synthetic (polyacrylamide) flocculants, ensuring high solids capture and adequate settling rates. The original P266 project was initiated in 1988 by scientists from two CSIRO Divisions (Mineral Chemistry and Mineral Process Engineering), who recognised that a multi-disciplinary approach was needed to identify ways of enhancing the performance of gravity thickeners in the minerals industry. With McLanahan Thickeners, producers can recover up to 90% of their water for reuse to createa more sustainableoperation. The practice of thickening or clarification is usually carried out in decantation tanks employing gravity settling or sedimentation. We oer a wide range of standard as well as custom designed tank designs including: The units can also be manufactured in stainless steel for more arduous environments such as at sea dredged aggregate sites. According to its transmission mode, it can be divided into central transmission type and peripheral transmission type; According to the number of working face, it can be divided into single layer, double layer and multi-layer thickener. The resulting new knowledge has been incorporated into sophisticated mathematical models which can be used to simulate full-scale thickener performance under a wide range of process conditions, thereby identifying the means to enhance full-scale performance. The feedwell may incorporate auto or forceddilution of the slurry feed to obtainthe optimum solids level as identified in the testing procedure. It is the most widely used concentration equipment in concentrator. He also founded Argo Consultinga technical and technical marketing consulting practice focused on providing mineral processing, water treatment and technical marketing consulting services to the mining industry. Mechanically, the patented Rakes are strongly braced to withstand the most severe over-load. Please fill out the contact form below to get the quotation price and engineer help. Why and when is a lifting device used in a Thickener? To start with, mineral thickener works on the principle of Gravity sedimentation and the most common construction of a thickener would be of iron or steel.The continuous thickener consists of a cylindrical tank. Hancock founded and owns Zeroday Enterprises which supplies chemical mix-feed systems, LTM conductive slurry level monitoring probes, peristaltic hose and tube pumps, mixers and flocculant and coagulant chemicals. The whole assembly is braced to the shaft by means of tie rods so that the rakes and rake arms form two trusses: one in the horizontal and one in the vertical plane. Fine particle recovery is needed to maximize thickener overflow clarity, minimize sands-slime separation in the bed which causes torque issues and to ensure bed solids flowability. Their activities ranged from fundamental surface chemistry to on-site measurements on full-scale units, as well as the development of new instruments and modelling approaches. If you need a thickener, you can consult our mining machinery technicians to select the most suitable thickener according to the actual situation.