Feed dilutionbased design of a thickener for refuse slurry of a coal. The present invention is directed to a method and apparatus for maintaining steady state conditions in a separator. Section 1 introduction this manual is an operation and maintenance guide or reference. With its simple design and small footprint, the powerdrum pdr drum thickener for sludge thickening is easy. Understanding the thickening process australian centre for. Control philosophy control systems are built around two fundamental and simple control loops. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. The pulp, which in the present example is the gluten pulp above mentioned, is fed into the launder 4 from whence it flows into the thickener through openings 7 back. Readers may only download, print and save electronic copies of whole works for. Thickener design pdf, mining thickener, thickener tank. We are concentrating on producing and selling machines such as jaw crusher, cone crusher, hammer crusher, ball mill, sand maker, mobile crushing plant. Feed dilutionbased design of a thickener for refuse slurry of a. Thickeners and clarifiers complete range of reliable and. Download download pdf customer tiwest location australia delivery year 2008 technology thickeners commodity mineral sands.
Thickener with central transmissionon this product details page, you can find 1,equipments purpose. The thickener controller adjusts the mass flow rate of the underflow in response to the influent mass flow signal. Improving thickener operation and control by means of a. Based on savings in labor for thickener operation, and lower costs to treat the thickener overflow, the payback period for thickener automation was estimated at less than 6 months. That signal is fed to a thickener controller which also monitors mass flow of the underflow. The thickening process, although operated successfully. Deflector plate feedwell radflow feedwell perturbed area feedwell type comparison in scale model thickeners both running at 3mhr rise rate. Control of the thickener operation in alumina production. Techniques and methodologies for improving thickener performance. Analysis of a range of industrial thickeners from the processing of gold ores, red. Pdf understanding the thickening process researchgate. A description of the sedimentation process during dynamic thickener operation a. Thickener control strategies and shortcomings in current thickener operations are discussed, including the.
Screwmax offers an easy and simple maintenance operation due to its low speed and low installed power compared to conventional systems. One tall thickener thus does the work of several relatively shallow thickeners of the same diameter. Gum thickeners work well in all types of hot and cold beverages. Application of theory to practice is explained at each stage, helping operators understand associated implications in each unit process.
Technology 127 the scum layer is important to consider in the design process as it also effectively reduces the volume of the tank. Integration of mclanahan highrate thickeners into a plant is simple. Dunn 2 paste 2014, vancouver, canada consolidation theory was applied to the settling of compressible slurries shirato et al. Understand the fundamental mechanisms of how settling thickening tanks function. Sizing and specifying a thickener can be challenging.
A lifting device promotes a dependable and continuous operation during plant upset conditions. Chapter 3 sludge thickening thickening is a procedure used to increase the solids content of sludge by removing a portion of the liquid fraction. Thickening is the most widely applied dewatering technique in mineral processing. Let our trained experts guide you through the available alternatives and. Control systems take care of most of the operation. There is a critical concentration in the settling process that the solids will achieve for.
Solids capture, however, was upgraded in that the solids level of the automated thickener overflow was much lower than that of the manual thickener. With reference to figure 93, a sludge with 1% solids thickened to 5% results in an 80% volume reduction since 5% 120. The invention relates to a thickener preparation for foods comprising an amylaceous product in powder form which is coated with an alkaline or alkalineearth stearate, the weight percentage of said stearate being not higher than about 2. Effect of settling test procedure on sizing thickeners. Us3679063a mechanism for operating thickener rake arms. Instrumentation and control of sedimentation equipment. Operating lights on the mill control panel indicate whether the rakes are fully lifted, fully lowered, moving up or down, turning or stopped. Flocculation is controlled by varying the flocculant pump speed to achieve a consistent flocculant. Many of these are easily measured, while some can be difficult. Aggregate densification in the thickening of flocculated suspensions in an unnetworked. Software for the design and simulation of gravity thickeners. An introduction, second edition, helps further understanding of the various methods commonly used in mineral beneficiation and concentration processes.
Consult with your health care professional about which product is appropriate for your specific needs. Nov 25, 2017 download download thickener design methods pdf read online read online thickener design methods pdf continuous thickener design thickener sizing calculation thickener operation manual thickener volume calculation thickener design calculations pdf high rate thickener design calculations thickener design equations thickener area calculation thickening of nonideal suspensions such as. For continuity of operation, it is necessary to have a transparent water tank to store the required water for diluting. Shear effects, introduced by raking within a thickener for example, are known to. Outotec thickening technologies 009 outotec provides expertise for the control and operation of the thickening process. Under industry sponsorship, csiro has undertaken to develop and validate a dynamic mathematical model describing thickener behaviour. Sludge thickening an overview sciencedirect topics. In operation, the motor 19 and other motivating devices are set into operation to effect rotation of the rake trusses 14 and 15 in a direction as indicated by the arrow in fig. At any horizontal plane in a continuous thickener operating under steadystate. The thickening equipment of gold cyanide factory adopted hydraulic motor driving center thickener, the capacity does not meet expected goals, and the timing of rake lost working hours, the working efficiency is low. With our worldwidestandardsetting drives, your thickeners and clarifiers will enjoy long. To illustrate, if waste activated sludge, which is typically pumped from secondary tanks with a content of 0.
Recovery from all height errors and false gamma and zeta parameters was effectively achieved 120 hours after the initial disturbance. Pdf techniques and methodologies for improving thickener. Specifically, an influent specific gravity and flow rate signals are monitored by an influent mass flow controller. Floor space is conserved, heat insulation is simple and effective, and power is reduced. Optimisation of thickener performance semantic scholar. Acknowledgement a manual testing procedure was used in a central control room, in which, at twohourly intervals, the process supervisor entered process variable data into the computer. If an object falls into the tank, immediately halt thickener operation to prevent torque overload. Hydraulic power pack the reliability and ease of maintenance of hydraulics are legendary. This is a very important step so here we discuss basic concentrate thickener operation. A concentration of 20% solids, which might be achieved by mechanical dewatering discussed in the next section, results in a 95% reduction in volume, with resulting savings.
For the mine to get its concentrate to the smelter it will have to be transported, by truck, train or ship. In this chapter we analyze different methods of thickener design that have been proposed in the literature, in the light of their physical foundations. Towards a unified model on the description and design of process. The clarified liquid overflow is delivered into the lauder 20 for disposal or return to the plant. Improve clarifier and thickener design and operation. Thickening, filtration and clarification in the phosphoric acid. Data analysis is completely manual and hence time consuming. Laboratory tests and plant operation have also established that a wellaerated pulp settles better than one in which aeration is incomplete. If this condition is not met, solids will build up and steadystate operation will not be possible. Thickener is polyurethane, hydroxyethyl cellulose, carboxymethyl cellulose, modified alkalisoluble.
Efficient operation is maintained in this upper zone over varying feed rates. Download download thickener design methods pdf read online read online thickener design methods pdf continuous thickener design thickener sizing calculation thickener operation manual thickener volume calculation thickener design calculations pdf high rate thickener design calculations thickener design equations thickener area calculation thickening of nonideal. Thickener with central transmission, view thickener with central. The advantages of sludge thickening in reducing the volume of sludge to be handled are substantial. Cyanidation and concentration of gold and silver ores. This is a very important factor for both tiwests operating costs and sustained operation, since the water lost to thickener underflow is evaporated in slimes cells and lost. View and download denver mca 150 instruction manual online. The thickener has a high sidewall and steep floor slope and with integrated automation it reacts to ever changing process conditions. The reason is that if, by accident, his hard hat ended up in the thickener that thickener may be down for days because of it. The revolutionary outotec high rate thickener has pioneered and redefined thickening and clarifying methods around the world. Eq button reptmup button skip tuning down button play pause button volume button skip. Operating lights on the mill control panel indicate whether the rakes are fully lifted, fully lowered, moving up or down. The general design of thickeners does not follow strict geometric proportions. Pdf thickener waste management in mineral processing to.
Thickener operation manual,our company is a largescale heavy enterprise that taking heavy mining machinery manufactory as main products and integrated with scientific research, production, and marketing. Thickeners and clarifiers complete range of reliable and cost. Improving thickener operation and control by means of a validated model. However, fluctuation of an interface level between clear and unclear areas of the thickener can effect flow rate adjustment. Instrumentation and control of sedimentation equipment abstract some of the process variables that are commonly monitored on a thickener are torque, rake height, bed level, bed pressure, feed rate and density, underflow rate and density, settling rate, and overflow turbidity. During the operation of the thickener described above, the liquid containing suspended materials is delivered to the center of the thickener through the pipe 22. Hence, zone settling places no depth demand on thickener design. Technology 124 consideration in urban locations where space is limited, as it can reduce the required area of subsequent treatment steps. The only way any object can be removed from the cone is by. Purchasing guide for thickeners viscosities may vary by brand.
Under normal conditions our example mill feed thickener rake drive will operate with the gear mechanism lowered, regardless of grinding or leaching operations. Outotec 2nd generation paste thickener provides ease of operation and reliability even in the most challenging applications. Improving thickener operation and control by means of a validated. The last thing that i would like to mention about thickeners is to do with their safety. Achieve a higher density underflow with our high compression thickener. Simic csiro division of mineral and process engineering, clayton, australia abstract various mathematical models describing thickener behaviour have been. In table i of the july article, improve clarifier and thickener design and operation, by joel christian pp. Outotec thickening technologies leading edge technologies for thickening and clarifying outotec is a global leader in the design, fabrication and supply of thickening and clarifying solutions for the minerals industry. The thickener or clarifier area must be sufficient to allow the slowest settling particle to reach the bed of compressing solids or bottom of the tank before its associated liquid has reached the overflow. These models have found limited use so far and few if any. Know the appropriate level of operations, maintenance and monitoring necessary to achieve solidsliquid separation in settling thickening tanks. This graphical method of performance predi c tion is illustrated in.
This brings us to the most important indicator of thickener operation, the overload alarm. Thickener operational and maintenance manual process what is the purpose of thickener in gold mining chat online pdf technology gravity thickening operation safety and maintenance manual jlg operation safety and maintenance manual manual and the service and maintenance manual maintenance application and operation. The powerdrum pdr drum thickener for sludge thickening is considered to be an easy and efficient sludge thickening solution prior to the dewatering process and can deal with biological sludge throughputs ranging from 15 to 180 m 3 hr. The etaq draws supernatant from the thickener surface and pumps into the radflow feed stream to achieve the perfect level of feed dilution for optimal focculation. Outotec directional autodil and outotec turbodil are the first thickening. Correct thickener and clarifier sizing ensures dependability and efficiency with a margin of safety for process upsets, allowing the.
The operator has time to correct the operation without impacting on production or damage to the thickener internals. Simic csiro division of mineral and process engineering, clayton, australia abstract various mathematical models describing thickener behaviour have been published. There is a spring arrangement attached to the drive mechanism up on top in such a way that when the arms begin plowing into sludge more than they were meant to, the spring. Aarne vesilind, in environmental pollution and control fourth edition, 1998. Pdf on jan 1, 2006, b j gladman and others published. Tiwest vane feedwell thickener retrofit, australia outotec. During plant rounds, regularly observe and record the drive torque indicator, which is the best indicator of mechanical overload. Sludge thickening is a process in which the solids concentration is increased and the total sludge volume is correspondingly decreased, but the sludge still behaves like a liquid instead of a solid. An algorithm has been developed to predict steady state thickener operation from. Have an overiew of potential advantages and disadvantages of operating a settling thickening tank. The powerdrum pdr is considered to be an easy and efficient sludge thickening solution prior to the dewatering process and can deal with biological sludge throughputs ranging from 15 to 180 m3hr.
In some plants fire a worker who wears his hard hat or takes foreign objects onto the catwalks above the thickeners. The outotec hct has been designed with a smaller footprint and higher walls than our high rate thickener or conventional thickeners. The thickener operation can be a batch or continuous process, with either cocurrent or. Take advantage of our pioneering thickening and clarifying methods with the outotec high rate thickener, including advances such as lowprofile triangular rake arms to reduce rake torque. A description of the sedimentation process during dynamic. In a continuous thickener, the area required for thickening must be such that the total solids flux volumetric flowrate per unit area at any level does not exceed the rate at which the solids can be transmitted downwards. With more than 30 years of experience in the development and manufacturing of drum thickeners, andritz separation has acquired unmatched expertise in this technology.
There is a spring arrangement attached to the drive mechanism up on top in such a way that when the arms begin plowing into sludge more than they were meant to, the spring pulls over a pointer on a scale put up where you can see it. Page 8 operation of remote handset operation button name power button mclk adj button preferences control operation. Mineral processing design and operations 2nd edition. Powerdrum pdr drum thickeners for sludge thickening.
Automatic sludge blanket control in an operating gravity. Gumbased thickeners usually contain xanthan andor cellulose gums. This probably is the reason why thickening rates in the cyanide plant are sometimes appreciably reduced when an ore is being milled which has partially oxidized in. The gts had the lowest capital and annual operating cost esti mates. The central drive thickener mainly used in the process of concentrate and tailings dehydration, equipment filtration equipment goldsmelting equipmentdry method and wet method cylinder sieve ungrouped. Recent developments in techniques and methodologies for improving thickener performance. The implications with respect to thickener operation and the requirements for the laboratory testing for thickener design are discussed. Continuous thickening by an operation called sedimentation is the. The scum layer associated with fs settling can be signi. In mining, when flotation is finished with the ore, and a final concentrate has been produced, often, both products will go to a concentrate thickener before it is dried for shipping. Steady state is maintained by controlling mass flow rates of influent to, and underflow from the separator. Control of the thickener operation in alumina production 1425 3.
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