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By H. Arima, Y. Kudo

In general, the iron content of zinc leach residue produced by sulphuric acid leaching from calcine is disposed as jarosite or goethite into a tailing dam. More recently, these iron residues have been treated pyrometallurgically to avoid waste disposal. The Iijima refinery selected a different zinc leach residue treatment process for iron control when it was established in 1971. The Iijima refinery is the only plant in the world that has processed a zinc leach residue by the combination of SO2 pressure leaching and O2 pressure hematite precipitation. The process enhances zinc recovery and recovers gold, silver, copper, lead and rare metals in saleable by-products. This paper focuses on the two stages of autoclave application in the zinc leach residue treatment process. The detailed flowsheet and recent advancements to improve the quality of by-products are discussed.

Jan 1, 2004

By Frank Hirthammer

"Nowadays, security in the lifecycle of explosives is more important than ever. Terror attacks all over theworld pushed the EU to decree a Commission Directive for the identification and traceability of explosives that set a series of requirements for involved manufacturers, distributors and end-users. The challenge was to find and implement a track and trace system for all concerned European companies byApril 5, 2015. Since then, countries worldwide have followed this example and implemented similarregulations."

Jan 1, 2017

By F. G. Hyde

Passage of the Public Utilities Regulatory Policy Act ("PURPA") in I 978 created an entirely new industry that is referred to today as the Independent Power Producers ("IPP"). Requirements of project owners, environmental compliance, project design, the financial community and most of all, the need to be a low-cost producer presented a unique situation for the sourcing and the utilization of fuels. Depending on the specific type of project being developed, (e.g. coal-fired, wood/biomass, natural gas, petroleum coke or a blend of several fuel types) and the type of boiler design, it is important to acquire fuels that will optimize both the project's operating efficiency and flexibility. This paper will focus on the acquisition of fuel for coal-fired projects, but will describe the necessary steps in the sourcing, contracting for, and the utilization of fuels and transportation resources in the IPP industry today.

Jan 1, 1996

By E. P. Williams

"Prince Edward Island, Canada's smallest Maritime Province, is located in the southwestern part of the Gulf of St. Lawrence. The Province is more or less centrally located in the Maritimes Basin, a large intermontane basin within the Appalachian orogenic belt. The Maritimes Basin is subdivided into sub-basins and uplifts which exhibit two dominant structural trends: east and northeast. The Basin is known to be petroliferous because of the seeps, shows, oil shales and albertite found in southern New Brunswick and northern Nova Scotia and the gas and oil produced from the Stony Creek field near Moncton, New Brunswick.Permian beds are exposed on the Island, mostly along sea-cliffs. A maximum thickness of about 5,000 feet of red beds -shales, sandstones and conglomerates -make up the sequence. Over most of the Island, the Permian section is much thinner. Four key wells (Mississippian tests) and several shallower tests have been drilled. The Pennsylvanian-Mississippian section thickens rapidly off the Port Hill Uplift at the northwest, where it is less than 4,600 feet thick, and continues to thicken to about 20,000 feet in the Cumberland Basin at the southeast. Geological and geophysical data combine to give us the structural picture of the deeper beds.Prospective reservoir rocks are primarily in the Missis-sippian Horton and Windsor groups. Prospects are:-1. on or over structural highs in the basement; 2. on anticlines or fault highs; 3. over or peripheral to salt domes or salt-core anticlines; 4. at truncation pinchouts of Mississippian prospective beds; 5. in basal sandstone or granite wash on the pre-Carboni-ferous basement; and 6. in facies traps at changes from sandstone to shale or porous to tight carbonate rocks."

Jan 1, 1967

By N N/A

To the members of The South African Institute of Mining and Metallurgy We have audited the annual financial statements set out on pages 239 to 245. These financial statements are the responsibility of the Institute?s Council. Our responsibility is to express an opinion on these financial statements based on our audit. Scope We have conducted our audit in accordance with statements of South African Auditing Standards. These standards require that we plan and perform the audit to obtain reasonable assurance that the financial statements are free of material misstatement. An audit includes: ?examining, on a test basis, evidence supporting the amounts and disclosures in the financial statements ?assessing the accounting principles used and significant estimates made by management ?evaluating the overall financial statement presentation. We believe that our audit provides a reasonable basis for our opinion. Audit opinion In our opinion, the financial statements fairly present, in all material respects, the financial position of the Institute at 30 June, 2000, and the results of its operations and cash flows for the year then ended in accordance with South African Statements of Generally Accepted Accounting Practice.

Jan 1, 2000

By Nils Schneider, Marc Peters, Stefan Frey, Andrea Fluck

Due to the worldwide population growth, the development of sustainable infrastructure and the exploration of renewable energies plays a key role to handle the rising megacity trends and to limit carbon footprint. Herrenknecht AG is a leading manufacturer of Tunnel Boring machines and has constantly endeavored through its extensive Research and Development programs to address limitations faced by the civil engineering industry as regards to construction equipment capabilities. New mechanized technologies, mainly coming from the tunnelling industry, have been developed by Herrenknecht AG as an efficient alternative to conventional civil engineering, where tailor-made concepts are required to comply with restricted conditions onsite. Very often this innovation led technology capability has meant making construction processes safer due to minimal human intervention and also far more productive due to higher performance as compared to other latest or conventional methods of construction. The rising need for even higher building structures and large-capacity bridges involve the development of innovative deep foundation technologies for on- and offshore operation. Conventional methods like bore piles reach their technical and economic limits under certain conditions. For building shafts and foundations, the mechanized Vertical Shaft Sinking Machine technology (VSM) from Herrenknecht AG is a proven innovation and has now been used in various onshore infrastructure projects worldwide to construct a total of 94 circular shafts in depths of up to 115 meters. It operates below the groundwater level, completely remote-controlled from the surface in a diameter range from 4.5 to 18 meters. Subsequently Herrenknecht noted that Offshore foundations, especially in non-drivable ground conditions such as soft and hard rock (e.g. limestone, sandstone, mudstone, granite etc. or soft soil with high density) and shallow continental shelf (water depth approx. 20-60m), presented construction challenges and equally an opportunity for building high performance equipment. The latter construction conditions usually requires drilled installation methods for applications such as harbor enlargements, bridge foundations and foundations for offshore wind turbines. The Offshore Foundation Drilling technology (OFD®) is Herrenknecht’s latest innovation, incorporating our learnings from the VSM and full-face Tunnel Boring machines, and the OFD® enables a rapid and economical offshore installation in such variable ground and rock conditions. This paper will discuss the technology behind the new mechanized technology of VSM and Herrenknecht’s latest innovation of the OFD® along with their respective application fields in foundations construction. The paper will further present in details, their range of benefits to the construction industry.

Nov 1, 2022

By E. C. Truesdale

IN recent years various problems in connection with research work on the preparation and properties of zinc-base alloys have required reliable information concerning the constitution of the zinc-rich portion of the iron-zinc equilibrium diagram. On numerous occasions rather positive indications were obtained that, for example, the solubility of iron in zinc was incorrectly represented on the current equilibrium diagrams. A careful study of all the available literature relating to the iron-zinc system led to the conclusion that much of the early work was unsatisfactory as measured by present standards of experimental accuracy, and as a result it was decided to redetermine the location of the liquidus curve and of adjacent portions of the diagram. Part I of this paper comprises a description of the experimental methods and a summary of the results by means of which the zinc-rich end of the iron-zinc diagram has been revised in the following ways: 1. Measurements of the solubility of iron in liquid zinc by several different sampling methods, leading to a relocation of the liquidus curve. 2. Microscopic, conductivity, and X-ray studies of the solid solubility of iron in zinc, which, together with thermal analyses, have resulted in new values for the solid solubility and the eutectic temperature and composition. 3. Heating and cooling curves, obtained by a refined differential method, leading to new locations for the two peritectic horizontals. In Part II of the paper the attempt is made to review all of the pub-lished work having a bearing on the constitution of the iron-zinc system, and to correlate the present results, and some recently published data

Jan 1, 1935

By J. H. Rowland

The Mine Improvement and New Emergency Response Act of 2006 (MINER Act) amended the Federal Mine Safety and Health Act of 1977 to improve the safety of mines. The MINER Act established a Technical Study Panel (the Panel) to provide independent scientific and engineering review and recommendations with respect to the utilization of belt air and the composition and fire retardant materials in underground coal mining (1). Because frictional heating is a common cause of belt fires, the Panel recommended that the Mine Safety and Health Administration (MSHA) evaluate the drum friction test to determine if such a test would contribute to conveyor belt safety beyond that provided by the Belt Evaluation Laboratory Test (BELT). This paper compares the results of the drum friction test to results from the BELT and large-scale tests for six different conveyor belts. The results are used to evaluate the drum friction test as a method to determine the fire resistance of conveyor belts.

Jan 1, 2011

Gullies are the vital in-stope excavations that provide access for mining personnel and material to, and mined ore from, the producing faces in the tabular hard rock mines. They pose a serious problem in most mines because they induce stress orientations, which, combined with blast damage, produce adverse rock fracture patterns that contribute to the loss of hangingwall and sidewall integrity. Rock-related injury statistics confirm this by highlighting gullies as the second-highest risk area in South African hard rock mines. Inappropriate gully geometries, poor blasting practice, and non-adherence to accepted standards worsen the problem. The aim of this work is, firstly, to provide guidelines to select the correct gully geometry and appropriate support for a particular geotechnical environment and, secondly, to review the practical issues behind gully safety and stability. In order to meet these aims, this paper reviews the available literature on gullies and their history, and reports on an industry-wide survey of practices and opinions. Then it covers observations from underground visits to 107 gullies situated in the respective geotechnical environments of the Basal Reef, Beatrix Reef, Vaal Reef, Carbon Leader Reef, Ventersdorp Contact Reef, Kimberley Reef, Kalkoenkrans Reef, Merensky Reef, and UG2 Reef. Despite the differing geotechnical conditions and gully geometries, common problems are experienced with geological structure, stress, and fracturing. Results from numerical modelling are also presented to help analyse the underground observations and to quantify the merits of the different gully layouts. It is concluded that there are no new techniques available to improve gully stability, but that significant improvements in safety are attainable by employing the correct gully geometry for the geotechnical environment, good blasting practice, and appropriate support.

Jan 1, 2002

By S Kasaneva

TheSan Cristobal gold district is located 110 km east of the port of Antofagasta, Chile. It contains the San Cristobal gold mine, where Niugini Mining Ltd. commenced a heap leach operation, with initial reserves of 10.1 million tonnes grading 1.34 g/t Au, in December, 1990. The San Cristobal district occurs within an upper Cretaceous-lower Tertiary magmatic arc. The main mineralisation occurs within a northwest trending subvertical zone, 1km long and 70 - 100 m wide, which contains rhyolite porphyry and minor breccia, and is locally termed the 'subvolcanic complex'. At the San Cristobal mine, most gold mineralisation occurs in subvertical quartz-pyrite veins which were emplaced in dilational sections of an imbricate fault system. The bulk gold resource comprises four ore shoots which formed where the vein system intersects the subvolcanic complex. Gold-bearing quartz-pyrite veins also occur at separate prospects, the Three Sisters and Sol prospects, west and south of the San Cristobal mine.   Hydrothermal alteration consists of potassic and propylitic assemblages related to intrusion of the subvolcanic complex. This alteration is overprinted by a phyllic stage which is associated with the emplacement of the quartz-pyrite veins. The oxide zone is 180 m thick, and contains native gold, electrum, limonite, and manganocarbonates. The underlying hypogene zone contains pyrite with minor chalcopyrite, sphalerite, galena, covellite, bornite, chalcocite, and arsenopyrite. Fluid inclusion studies indicate that the deposit formed at approximately 270¦C, and the mean salinity of the fluid was 4% NaCl equivalent. These observations enable the San Cristobal deposit to be classed as a porphyry- related, mesothermal quartz-vein system of the low sulphidation type.

Jan 1, 1995

By Kenneth Eltschlager, Jim Ratcliff, Michael Mann, Edward Sheehan

The Appalachian Blaster Certification Delegation initiated a study to compare the consistency of measurements from blasting seismographs. Six blasts were monitored at surface coal mines in West Virginia, Maryland, and Ohio. A total of seven different makes were deployed during the tests, with as many as seven models from five different manufacturers compared during any one blast. Great care was taken to bury the geophones in identical fashion. The variations in seismograph readings were compared to the International Society of Explosives Engineers’ Performance Specifications for Blasting Seismographs. Between 4 and 125 Hertz, the ground vibration amplitudes should be within ±5% and airblast amplitudes should be ±1 decibel. For each of the three mutually perpendicular ground vibration channels and the acoustic channel, the median value of all the units was used as a baseline for comparison. The six blasts monitored had median peak particle velocities ranging from 0.42 to 3.47 inches per second (in/s) (10.7 – 88.1 mm/s) and median airblasts ranging from 124 to 135 decibels (dB). There were 46 seismograph recordings for the six blasts. Eighteen (39%) of the 46 maximum peak particle velocities varied more than ±5% from the median. A total of 138 (3 × 46) component particle velocities were recorded, with 50 (36%) of the readings varying more than ±5% from the median. For airblast comparison, 43 recordings were obtained, with seven (16%) varying more than ±1 dB of the median. Variances may be attributable to blasting seismograph differences, variations in field deployment, and relative locations of the geophones. Full waveform seismic and acoustic overlays for individual blasts showed encouraging conformity with some slight anomalies

Jan 1, 2015

By A. Buchanan, M. Mirnezami, A. L. Restrepo, J. A. Finch, M. S. Hashemi

Settling rate studies on slurries from Cu/Zn flotation plants occasionally revealed two aggregation maxima at pH 8-10 and 10-12. From measurements on sphalerite and silica suspensions the double maxima were replicated by Zn ions (pH 8-10) and Mg ions (pH 10-12) corresponding to the presence of zinc hydroxide and magnesium hydroxide, respectively. A combination of chemical and electrostatic bridging by the hydroxides is considered to be the aggregation mechanism.

Jan 1, 2003

By K. Darcovich

The wettabilities of agglomerates made from coals of several different ranks were measured by the adhesion technique. Oil levels from 0 to 10% by weight were used. As was expected, it was found that higher-rank coals are more easily oil-wetted and that the surface properties of the agglomerates correlate with agglomeration recovery and ash removal data.

Jan 1, 1992

By R. R. Estill

THE rank of the Ruhr coal ranges from a high volatile bituminous coal to an anthracite, depending to some extent on the original depth of the seam. The average Ruhr coal corresponds to a soft bituminous American coal of a coking quality. The average thicknesses of individual coal seams being mined are also comparable (59 in. against 65 in. in the United States). However, consideration of seam conditions and mining conditions other than those just mentioned emphasizes differences rather than similarities with United States soft coal. In general, the Ruhr seams now being mined are much more folded and inclined than American seams. Dips of 20' and 30" are common in seams now being worked, and 30 pct of the coal reserves in the district are in seams dipping more than 35". Only on the tops and bottoms of folds do we find rather flat coal seams. In addition to the folding there is extensive displacement by cross faulting plus a certain amount of strike faulting of an overthrust nature, which results locally in doubling or omission of seams. Because of the long history of mining in the Ruhr, nearly all coal lying near the surface has long since been mined out, and we find that the average depth of mining is at present about 2300 ft below the surface. Deep mining, folding, and faulting result in seam conditions requiring a great deal more roof support than one finds in American soft coal mines. In fact only in the anthracite district and the Rocky Mountain and Pacific coal fields do we find somewhat similar conditions. It is easy to say, therefore, that the problem of mechanization of coal cutting and loading in the German mines is quite different from that which we have so effectively met in America with our mobile cutters and loaders, duck bill loaders, and a room and pillar system of mining our drift and slope mines. Partly because of more limited coal reserves, the traditional German mining system is largely the longwall method, which gives an almost complete coal recovery. Backfilling must be extensively practiced to protect the longwall faces, the over and underlying seams and workings, and especially the surface industrialized areas and barge canals. The German engineers have accordingly concentrated their efforts on the design of cutters, loaders, and conveyors suitable to longwall methods rather than room and pillar methods. Undercutters with cutter bars like American models have been in use in the Ruhr since well before World War 11. In 1941 they accounted for 8.5 pct of the production. This percentage, of course, includes coal which was undercut but nevertheless had to be broken down with air hammers or with explosives. The most common of these cutters is the Eickhoff Standard cutter (see fig. 1). This machine does about 95 pct of the undercutting in the Ruhr today, and is available with either compressed air or electrical power and in at least four different sizes. A variation of the cutter is this one with two cutter bars (fig. 2). At the end of 1947 about 200 of these machines and similar cutters were accounting for 13.2 pct of the total production, a production which was, however, only 60 pct of the 1941 production rate, so that the actual cutter tonnage was only up to a small amount over 1941. In 1941 about 3 pct of the production was accounted for by shearing machines making their cut perpendicular to the longwall face. They were similar to those used in the States. These machines are today considered obsolete and now account for only 0.7 pct of the total production. They are located at only a few mines and at present do not seem to have much of a future in the Ruhr. For the future, the Ruhr miner is looking forward to rather extensive mechanization of face work, with two major types of equipment being developed almost simultaneously. On one hand there is the development of cutter loaders for use in relatively hard coal. They represent the further extension of ideas developed after relatively long experience with the Eickhoff cutter. On the other hand there has been since 1942 an intense interest in the Ruhr in the development of face-stripping methods, particularly by the Kohlenhobel (coal plow) and its modification. At the end of 1947 these cutter loaders, Kohlen-hobels and scrapers together were actually accounting for only about 1.4 pct of total production while air hammers still broke 77.1 pct and as much as 1.2 pct was actually broken by hand picks. However,

Jan 1, 1951

By R. R. Estill

THE rank of the Ruhr coal ranges from a high volatile bituminous coal to an anthracite, depending to some extent on the original depth of the seam. The average Ruhr coal corresponds to a soft bituminous American coal of a coking quality. The average thicknesses of individual coal seams being mined are also comparable (59 in. against 65 in. in the United States). However, consideration of seam conditions and mining conditions other than those just mentioned emphasizes differences rather than similarities with United States soft coal. In general, the Ruhr seams now being mined are much more folded and inclined than American seams. Dips of 20' and 30" are common in seams now being worked, and 30 pct of the coal reserves in the district are in seams dipping more than 35". Only on the tops and bottoms of folds do we find rather flat coal seams. In addition to the folding there is extensive displacement by cross faulting plus a certain amount of strike faulting of an overthrust nature, which results locally in doubling or omission of seams. Because of the long history of mining in the Ruhr, nearly all coal lying near the surface has long since been mined out, and we find that the average depth of mining is at present about 2300 ft below the surface. Deep mining, folding, and faulting result in seam conditions requiring a great deal more roof support than one finds in American soft coal mines. In fact only in the anthracite district and the Rocky Mountain and Pacific coal fields do we find somewhat similar conditions. It is easy to say, therefore, that the problem of mechanization of coal cutting and loading in the German mines is quite different from that which we have so effectively met in America with our mobile cutters and loaders, duck bill loaders, and a room and pillar system of mining our drift and slope mines. Partly because of more limited coal reserves, the traditional German mining system is largely the longwall method, which gives an almost complete coal recovery. Backfilling must be extensively practiced to protect the longwall faces, the over and underlying seams and workings, and especially the surface industrialized areas and barge canals. The German engineers have accordingly concentrated their efforts on the design of cutters, loaders, and conveyors suitable to longwall methods rather than room and pillar methods. Undercutters with cutter bars like American models have been in use in the Ruhr since well before World War 11. In 1941 they accounted for 8.5 pct of the production. This percentage, of course, includes coal which was undercut but nevertheless had to be broken down with air hammers or with explosives. The most common of these cutters is the Eickhoff Standard cutter (see fig. 1). This machine does about 95 pct of the undercutting in the Ruhr today, and is available with either compressed air or electrical power and in at least four different sizes. A variation of the cutter is this one with two cutter bars (fig. 2). At the end of 1947 about 200 of these machines and similar cutters were accounting for 13.2 pct of the total production, a production which was, however, only 60 pct of the 1941 production rate, so that the actual cutter tonnage was only up to a small amount over 1941. In 1941 about 3 pct of the production was accounted for by shearing machines making their cut perpendicular to the longwall face. They were similar to those used in the States. These machines are today considered obsolete and now account for only 0.7 pct of the total production. They are located at only a few mines and at present do not seem to have much of a future in the Ruhr. For the future, the Ruhr miner is looking forward to rather extensive mechanization of face work, with two major types of equipment being developed almost simultaneously. On one hand there is the development of cutter loaders for use in relatively hard coal. They represent the further extension of ideas developed after relatively long experience with the Eickhoff cutter. On the other hand there has been since 1942 an intense interest in the Ruhr in the development of face-stripping methods, particularly by the Kohlenhobel (coal plow) and its modification. At the end of 1947 these cutter loaders, Kohlen-hobels and scrapers together were actually accounting for only about 1.4 pct of total production while air hammers still broke 77.1 pct and as much as 1.2 pct was actually broken by hand picks. However,

Jan 1, 1951

By Lucia Kuizon

The Morongo Wilderness Study Area (WSA) is in south central San Bernardino County, California. U.S. Bureau of Mines examined the area during the fall of 1983. No mines, prospects, leases, or mining claims were found in the WSA. There are no known mineral deposits within the study area boundaries. Sand and gravel in the area is suitable for many types of construction uses, but similar and larger deposits outside the WSA are closer to markets. No energy resources have been identified in the WSA.

Jan 1, 1984

By Richard W. Watson

Card-gap and projectile impact sensitivity data are presented for a wide variety of explosive compositions tested at the Bureau of Mines in more or less standard test geometries. The results of both tests are in good agreement in that they provide the same sensitivity ordering for different subclasses of explosives. Least sensitive were homogeneous liquids that did not exhibit a tendency to undergo low-velocity detonation, ammonium nitrate-fuel oil, and most cast military explosives. Of intermediate sensitivity were pressed and powdered military explosives, cast pentolite, permissible and non- permissible water-based explosives, and one commercial two-component explosive. The most sensitive were permissible and nonpermissible dynamites and explosives susceptible to low-velocity detonation.

Jan 1, 1973

By Kenneth G. Broadhead

The objective of this rare-earth oxalate study by the Bureau of Mines was to determine systematically by radiochemical techniques what effects, if any, could be attributed to the several variables--temperature, digestion time, acid concentration, rare-earth concentration, oxalic acid concentration, stirring, and the presence of other rare-earth ions. A Latin Square experimental design was used to evaluate statistically some of the variables. Precipitation losses ranged from near zero to about 7 percent, and mineral acid and rare-earth concentration were the predominant factors affecting completeness of precipitation. Quantitative oxalate precipitation of the rare-earth elements was achieved by controlling the experimental conditions as follows: (1) Maintaining rare-earth concentrations above 0.01M; (2) stirring the mixture several minutes after precipitation; (3) using an adequate (two to five-fold) excess of oxalic acid; (4) precipitating at room or iced temperature and digesting for at least 1 hour; (5) avoiding an excess of mineral acid and, if possible, maintaining the pH above 2.0; and (6) avoiding excess complexing agents such as EDTA (ethylenediaminetetraacetic acid). In the past 20 years research aimed at developing more efficient separation and purification techniques applicable to the rare-earth elements and yttrium has been extensive. Common to most of these procedures has been the use of oxalic acid to precipitate this group of elements selectively. However, this particular use of oxalic acid has a much earlier origin; its application in precipitating yttrium was first reported by Mosander (8)4 in 1843. Despite long and popular employment of this technique, only limited and somewhat conflicting data are available regarding the many factors affecting the degree of rare-earth oxalate precipitations.

Jan 1, 1961

By Emily Sing, Ashim Gajurel, Thomas Pennington, William Brown

The Pardee Chemical Feed Shaft Project involves construction of two new chemical feed shafts to improve raw water treatment capabilities at the East Bay Municipal Utility District’s (EBMUD) Pardee Reservoir in Valley Springs, California. The project includes construction of two 250-foot deep, 16-inch diameter stainless steel chemical feed shafts that penetrate an existing 8-foot diameter concrete lined conveyance tunnel. The design approach required the shafts be installed using top-down drilling methods and within a strict verticality tolerance (0.1%). Innovative precision drilling techniques ensured that the shafts penetrated the tunnel in their planned locations and the installed chemical feed lines would function as designed. Challenges included extremely limited access to the tunnel because of a requirement to maintain the tunnel in service during construction. This paper discusses the overall project’s design and construction approach, including unanticipated conditions that the project team faced and how these conditions were managed and overcome through collaboration between the contractor, designer, and owner.

Dec 1, 2022

The Operation of the LAROX PF-50 Pressure Filter at 'Ellatzite-Med' Flotation Plant, Bulgaria The implementation of Larox pressure belt filter, type Larox PF-50 provided within 6˜8% moisture content of the produced copper concentrate, which allowed good market realisation. The start-up of the pressure filter in 2009 reduced the electricity costs several times and had a positive impact on the technological regime of flotation. This article reveals the investigation results from the operation of the pressure filter according to different situations (density of the pulp, time for filtration, pressure of the material, pressure of the drying air, time for drying with air and other factors). The investment made in the pressure filter application is a guarantee for the successful operation of 'Ellatzite' flotation plant, Bulgaria in the coming years.

Sep 13, 2010