PASTE WITHOUT PAIN MAGRA ULTRASEP 2000 HIGH PERFOR MANCE THICKENER/CLARIFIER

1. PASTE WITHOUT PAINMAGRA ULTRASEP 2000 HIGH PERFOR MANCE THICKENER/CLARIFIER Magra Process Engineering (Pty) Ltd Phone: +27 18 468 1540 Fax: +27 18 468 - 8492 Cel: +27 82 372 3404 E - mail: wallie@magra.co.za The Magra Ultrasep 2000 High Performance Thickener was developed to fulfil the role of a thickener/reactor as well as a clarifier MAGRA ULTRASEP 2000 THICKENERS ARE PROTECTED BY S.A. PATENT NO. 2000/0910 WE ARE THE ONLY THICKENER SUPPLIER PROVIDING PASTE WITHOUT RAKES - SEE THE MAGRABRATOR a) The most affordable, versatile and user friendly thickener on the market b) Highest performance per unit area c) Lowest operating cost ever d) Fewest parts - all non moving as well e) Quickest response of any known thickener f) Combined thickening and clarification now realised g) Extremely good trustworthy behavior displayed h) Ingenious design ensures small forces i) Turnkey projects with best delivery and customer satisfaction j) We offer the best available expertise on High Performance Thickeners and Clarifiers AdvancedProcessing Technology Page-down to advance or page-up to revert

2. MAGRA PROCESS Walkway and hand rails on top of supporting beams Tank The Magra Ultrasep 2000 High Performance Thickener/Clarifier is housed in a 60° cylindrical/ conical or pyramidal tank or a shaft formed to the same dimensions as the tank (underground applications). The design is an affordable alternative when retrofitted into a disused pachuca tank. All internals are suspended from two supporting beams over the top of the housing structure. The support beams also provide for a walkway with handrails.

3. MAGRA PROCESS Overflow Launder Feed Pipe Overflow & Feed Arrangement Available Materials for Internals: Normal structural or stainless steel and light-weight fiberglass depending on location, mobility and acidity of materials. Components are also painted to customer specifications or rubber-lined if needed. Mixing chamber The mixing chamber is a cylindrical pipe suspended in the centre of the tank at the top. Feed enters the mixing chamber through a T-piece manifold with 45° outlet bends, each facing 30° down. This provides good mixing and dispersion of flocculant which is normally added directly into the mixing chamber as well. Total flocculation should be achieved by the time the feed particles exit the bottom of the mixing chamber. Overflow launder The overflow launder is octagonal in shape, have V- notches cut all round, is height adjustable and placed between the mixing chamber and the vertical side of the tank. Conical baffle A conical baffle is inserted near the top of the tank and an annular throat is formed between the vertical wall of the mixing chamber and the inner periphery at the bottom of the conical baffle. Overflow Pipe Mixing Chamber Conical Baffle

4. MAGRA PROCESS Dewatering system The dewatering pipe is suspended centrally inside the mixing chamber with it’s 60° collector cone extending from the bottom of the mixing chamber, thereby deflecting the feed and insuring even distribution of solids. Dewatering pipe Collector Cone

5. MAGRA PROCESS Consolidation cone The consolidation cone is shaped like a triangular doughnut and is suspended below the collector cone in the upper (low density) compaction zone in order to provide as little flow restriction as possible The increased inclined surface area covers almost three times more projected area than a singular conventional cone thus greatly improving consolidation and dewatering where it matters most Pressure Difference 1 2 Consolidation cone

6. MAGRA PROCESS A suspension of solid particles in the carrier liquid at low density enters the mixing chamber and mixes with the flocculant. The mixing chamber extends down to the free settling zone. The downward velocity of the suspension suddenly decreases passing from the mixing chamber (small diameter) to the thickener tank (larger diameter). The sudden decrease in the downward velocity allows the large particles to settle out and the small particles are carried upward and accelerate through the annular throat creating turbulence and collisions. The settling velocity of the fines particles increases as the particles grow larger. The upward flow velocity above the throat decreases until the top of the conical baffle is reached.When the settling velocity of the particles exceeds the upward velocity, the particles start to drop downwards and on its downward path collisions occur with upward moving particles. This causes agglomeration and the particles finally become large and heavy enough to drop back through the annular throat into the free settling zone. The fine particles form a floc bed which act as a filter and a clarified zone is formed above the floc bed. Clarified liquid overflows into the overflow launder. The fines particles dropping down from the floc bed mixes with the feed exiting from the mixing chamber diverted by the conical collector. Coagulation of fines now takes place and fewer fines are carried upward through the throat. This increases the capacity of the Ultrasep 2000 Thickener far beyond any other known unit. Flow Diagram - Low Density Feed

7. MAGRA PROCESS The passage of solids particles exiting the mixing chamber and annular throat are intercepted by the inclined surfaces of the consolidation cone. Consolidation takes place and the particles slide or roll down the inclined surfaces. Liquid separating the solids is displaced and collects below the collector cone. Some liquid returns to the free settling zone resulting in continuous dilution of the free settling zone leading to faster settling of solids particles. Liquid collected under the collector cone move up the dewatering pipe. Upward movement of the liquid in the dewatering pipe is caused by the difference in pressure at position 1 (liquid pressure) and position 2 (pressure due to liquid zone above floc bed plus floc bed density and feed density). The liquid in the dewatering pipe contains unspent flocculant which overflows into the mixing chamber and thereby acts to dilute and flocculate the feed. A continuous internal dilution cycle is created.. Dilution further reduces flocculant consumption (grammes/tonne) and settling rate is increased. Density increases with consolidation and compaction due to the intergranular contact pressure between the particles. The depth of the compaction zone can be used to control the underflow density. With an increase in height, the residence time increases and together with the additional pressure being exerted on the compaction zone allows for liquid to escape from the compaction zone thereby increasing the density. 1 2 Flow Diagram - Low Density Feed

8. MAGRA PROCESS HIGH DENSITY FEED UP TO DENSITY OF 1,55 A suspension of solid particles in the carrier liquid at high density enters the mixing chamber and mixes with the flocculant. Because of the high density of the suspension there will be a level displacement in the mixing chamber. The top edge of the mixing chamber is modified to include V-notches similar in shape to the overflow launder V-notches and is also lowered to the level of the overflow launder. A second internaldilution cycle is now created. This causes an increase in the upward flow velocity which is now much lower with less dewatering required at high feed density compared with low feed density to obtain the same underflow density. Increasing the upflow velocity to the previous low density condition will not affect the operation. The thickener again operates like a low feed density unit. Flocculant consumption are at the same level as a low feed density unit. The Ultrasep 2000 High Performance Thickener is self regulatory and both the internal dewatering cycles adjust to accommodate feed conditions. Flow Diagram High Density Feed