Mozley Multi-gravity Separator Research Articles

IMPLEMENTATION OF FLOTATION TO RECOVER LEAD AND BARITE FROM KOMSHECHE MINE JIG TAILINGS

With the increase in the basic metal prices, including lead, in the global markets, the processing of this precious metal, particularly for low-grade deposits, has a high economic justification. Investigating the extraction of lead minerals, including galena which is one of the minerals associated with barite, is considered one of the products of barite by-products. The purpose of this research was to study on the potential of producing high-grade barite, and recovering lead concentrate as a by-product from the jig tailings of the Komsheche barite mine. The prepared sample was subjected to mineralogical studies, and the obtained results indicated that the sample contains barite, iron hydroxides and galena as the dominant minerals and the degree of liberation was 90-95% in the size of 100 microns. The work index of the sample was obtained by the standard bond ball mill which was 8.72 kWh/t, indicated that the sample was not hard. The lead and barite grades in sample were 0.34% and 64.83%, respectively. Considering the high specific gravity of lead and barite, the processing tests were carried out in 2 stages of primary pre-processing using Mozley multi-gravity separator and then enrichment by flotation approach. After the end of the Mozley tests, the grade of lead reached to 0.6%, some fines were removed, and the classified sample was prepared for the next stage, flotation. At the end, the grade of lead increased from 0.6% to 53% with a final recovery of 73.65% and separation efficiency was 73.48%. Also, the specific gravity and grade of barite reached from 3.9 g/cm3 and 67% to 4.4 g/cm3 and 95%, respectively. These values are remarkable and meet the needs of the industry.

Optimisation of a Multi-Gravity Separator with Novel Modifications for the Recovery of Ferberite

Tungsten is considered by the European Union as a critical raw material for future development due to its expected demand and scarcity of resource within Europe. It is therefore, critical to optimize European tungsten operations and maximise recoveries. The role of enhanced gravity/centrifugal concentrators in recovering tungsten from ultra-fine fractions should form an important part of this aim. Reported herein are the results of investigations to improve efficiency of Wolf Minerals’ Draklends mine, a major European tungsten mine, by recovering saleable material from a magnetic waste stream of a low-intensity magnetic separator using an enhanced gravity concentrator. The mine hosts wolframite and ferberite as the main tungsten bearing mineral species. A Mozley multi-gravity separator (MGS) C-900 was selected as it is suited to exploiting small variations in mineral density to affect a separation. Working with a current manufacturer, a novel scraping blade system was tested. To assess the MGS in a statistically valid manner, a response surface methodology was followed to determine optimal test conditions. The test programme showed that the most important parameters were drum speed and wash water rate. Under optimal conditions the model predicted that 40% of the tungsten could be recovered above the required grade of 43% WO3.

An Efficient Process for Recovery of Fine Coal from Tailings of Coal Washing Plants

Gravity concentration of hard lignites using conventional jigs and heavy media separation equipment is prone to produce coal-rich fine tailings. This study aims to establish a fine coal recovery process of very high efficiency at reasonable capital investment and operational costs. The technical feasibility to upgrade the properties of the predeslimed fine refuse of a lignite washing plant with 35.9% ash content was investigated by employing gravity separation methods. The laboratory tests carried out with the combination of shaking table and Mozley multi-gravity separator (MGS) revealed that the clean coal with 18% ash content on dry basis could be obtained with 58.9% clean coal recovery by the shaking table stage and 4.1% clean coal recovery by MGS stage, totaling to the sum of 63.0% clean coal recovery from a predeslimed feed. The combustible recovery and the organic efficiency of the shaking table + MGS combination were 79.5% and 95.5%, respectively. Based on the results of the study, a flow sheet of a high-efficiency fine coal recovery process was proposed, which is also applicable to the coal refuse pond slurry of a lignite washing plant.

Treatment of lead mine waste by a Mozley multi-gravity separator (MGS)

Increasing environmental awareness and pressure is focusing attention on metal removal leading to the accelerated development of contaminated land reclamation technologies. The majority of wastes associated with base metal mining activity are fine tailings. Depending on the age and history of the metals, their characteristics vary considerably and each deposit requires individual characterisation. This paper investigates the treatment of lead–zinc mine wastes by the multi-gravity separator, a novel mineral processing machine. A laboratory study was carried out to find the most effective conditions using parameters such as drum angle and size fraction. A material and mass balance for the laboratory system has demonstrated that approximately 12% of the Pb can be removed in the form of concentrate with 12% Pb content.

石炭の国際的市況変化と新規環境技術の展開 Ｍｕｌｔｉ‐Ｇｒａｖｉｔｙ Ｓｅｐａｒａｔｏｒによる選炭微粒ズリからの可燃分回収

The recovery of fine combustible matter from coal washery waste was investigated using a laboratory/pilot scale Mozley multi-gravity separator (MGS). The effects of parameters such as drum rotational speed, wash water rate and feed rate on the yield, the recovery of combustible matter, and the ash content of the concentrate were studied. It was found that the yield, recovery and ash content decreased with the decrease in wash water rate and with the increase in drum rotational speed and feed rate. It is estimated that these separation performances depend on the amount of particles retained inside the MGS drum. Because MGS was not suitable for the separation of very fine particles of clay minerals from coal washery waste, we suggested introducing a two-inch hydrocyclone after MGS treatment to effectively eliminate these clay minerals. A process for the recovery of fine combustible matter from coal washery waste using four-inch and two-inch hydrocyclones and MGS was then proposed. The yield, combustible matter recovery, calorific value and ash content of concentrate obtained from the process were 37 %, 57 %, 5940 kcal/kg and 18 %, respectively. These results show the technical advantages of the proposed process to reduce waste materials and increase the recovery of salable products.

Ｍｕｌｔｉ‐Ｇｒａｖｉｔｙ Ｓｅｐａｒａｔｏｒによる廃コンクリート微粉からの細骨材およびセメント水和物の回収

Fine waste concrete smaller than 5mm obtained from a recycling plant of waste concrete was used as feed and ground by a wet attrition mill. Recovery of the fine aggregate and cement hydrate powder from the ground fine waste concrete was investigated using a laboratory / pilot scale Mozley multi-gravity separator (MGS). The water absorption of the fine aggregate obtained as the high specific gravity product was less than 3.5 % and the dry density was larger than 2.4 g/cm3. The powder obtained as low specific gravity product contained about 29 % of fine aggregate. The reference for normal clinker and the mixture prepared by mixing the reference materials with 38 wt% of the powder were heated at 1,500 °C, with the hydraulic modulus adjusted to 2.18, the silica modulus to 2.8, and the iron modulus to 1.64. The phases of the clinker were identified and quantitatively determined by a microscopic point-count procedure and by the Rietveld analysis using XRD data. There was good agreement in the clinker minerals of the reference and the mixture clinkers. These results show that the fine aggregate and cement hydrate powder recovered from fine waste concrete by MGS can be recycled in cement and concrete production.

Separation and Mineralogical Analysis of Bayer Red Mud

AbstractThis paper describes preliminary work to assess the potential for recovering valuable components from Queensland Alumina Limited (QAL) red mud by physical beneficiation. Upgrading of Weipa bauxites residue was trialed using a 50 mm hydrocyclone and a Mozley Multigravity Separator (MGS) to recover desilication product (DSP) and TiO2 fractions. The mineralogy of the original red muh and the various sub‐fractions produced was studied by chemical assay, selective leaching, XRD and SEM techniques.DSP is present in QAL red mud in two forms: (i) as balls in the size range from 0.8 to 10 μm that appear to be liberated; and (ii) as finely grained DSP intermixed with the other minerals. The hydrocycloning tests produced a DSP rich (39.5 wt%) fraction at 89% recovery from a feed containing 31.9 wt.% DSP. This represents an upgrade (enrichment) of 1.24 times. These results suggest that the greatest DSP enrichment will be achieved by targeting the 0.8 to 10 μm DSP balls.The richest TiO2 fraction produced varied from 20 to 36 wt.% TiO2 from a feed value of 7 wt.% at a recovery of 7.5%. Mineralogical examination showed that most of the TiO2 in this fraction was as liberated particles in the size range 8 to 20 μm. Most of the TiO2 particles in the other fractions were not fully liberated from mainly iron minerals.The present work indicates that it is possible to further upgrade DSP fractions by investigating finer particle separation techniques, e.g. smaller, 25 mm and 10 mm, hydrocyclones.

Applicability of Mozley multigravity separator (MGS) to fine chromite tailings of Turkish chromite concentrating plants

The total amount of fine chromite gravity tailings in Turkey is around 3,000,000 tons with a quite high Cr 2O 3 content of about 9–20%. These fines are produced as a result of the inefficiency of conventional separation equipment at fine particle size due to finely grained feed and optimization problems. In this study, the applicability of enhanced gravity concentration technique for recovering fine chromite from the gravity tailings of four different chromite concentrators of Turkey is investigated using a laboratory/pilot scale Mozley multigravity separator (MGS). The results of the investigation have revealed that a considerable amount of fine chromite can be produced from the fine gravity tailings of Turkish chromite concentrating plants. The amount of recoverable chromite fines from the stockpiled or ponded Turkish chromite gravity tailings is around 300,000–400,000 tons. Two types of MGS fines recovery units were proposed. Type A is foreseen for treatment of already stockpiled tailings and Type B is thought as a retrofit in an existing plant for recovering of fines during production. Preliminary economical evaluations showed that both types of MGS fines recovery units have very short pay back times.

Beneficiation of bastnaesite by a multi-gravity separator

The preconcentration of bastnaesite of Beylikahir ore was achieved by attrition scrubbing of the original ore crushed to −1.65 mm. After scrubbing the sample at 50% solid pulp density for 1 h, the pulp was diluted and deslimed by cycloning. The slime (cyclone overflow) that was collected as a preconcentrate, assayed 28% REO with 72.6% recovery. The preconcentrate was fed to a Mozley multi-gravity separator (MGS) for further upgrading. As a result, a bastnaesite concentrate with 35.5% REO grade and 48% recovery (on original ore basis) was produced. Chemical analysis of the concentrate was as follows: Ce, 13.75%; La, 11.81%; Nd, 2.30%; Pr, l%; Sm, 0.15%; Y, 0.064%. H 2SO 4 curing and water leaching of the preconcentrate indicated that >75% of REE could be taken into solution.

Ultrafine tantalum recovery strategies

The Bernic Lake mine of the Tantalum Mining Corporation of Canada is the largest producer of tantalum concentrate, high purity spodumene, as well as cesium and rubidium ores, in North America. Tantalum is one of the “high-tech” materials, and some of its applications are briefly discussed. Tantalum recoveries have consistently been in excess of 70%, from ores grading less than 0.1% Ta 2O 5. The primary target for increased recovery is in the ultra fine size ranges. This paper discusses ultrafine recovery strategies which have been attempted, including flotation and “slime” gravity concentration devices such as Bartles-Mozley Separators and Crossbelt Concentrators. Testwork has now been carried out on the new generation of fine gravity devices; centrifugal separators. Data from four such devices — Mozley Multigravity Separator, Kelsey Jig, Falcon concentrator and Knelson Concentrator — have been compared with the existing technology, which has resulted in modifications to the fine tantalum recovery circuit.

Production and properties of corrosion resistant tantalum carbide based materials: T.N. Shishkina et al, Poroshkovaya Metallurgiay, No 7, 1992, 101–106. (In Russian)

The Bernic Lake mine of the Tantalum Mining Corporation of Canada is the largest producer of tantalum concentrate, high purity spodumene, as well as cesium and rubidium ores, in North America. Tantalum is one of the “high-tech” materials, and some of its applications are briefly discussed.Tantalum recoveries have consistently been in excess of 70%, from ores grading less than 0.1% Ta2O5. The primary target for increased recovery is in the ultra fine size ranges. This paper discusses ultrafine recovery strategies which have been attempted, including flotation and “slime” gravity concentration devices such as Bartles-Mozley Separators and Crossbelt Concentrators. Testwork has now been carried out on the new generation of fine gravity devices; centrifugal separators. Data from four such devices — Mozley Multigravity Separator, Kelsey Jig, Falcon concentrator and Knelson Concentrator — have been compared with the existing technology, which has resulted in modifications to the fine tantalum recovery circuit.

Process improvements for fine cassiterite recovery at Wheal Jane

Increasing environmental pressure and lower tin prices have forced some tin smelters out of business and those that remain in operation in general rely upon receipt of high grade tin concentrates in order to satisfy environmental and/or economic constraints. Carnon management have successfully kept one step ahead of these changes by continually striving to produce cleaner tin concentrates. Over a period of some 12 years the fine cassiterite concentrate grade has increased from 5% to 60%Sn without which the company would not have been able to continue marketing it's product. This paper briefly describes the evolution of the tin flotation circuit at the Wheal Jane mill with particular reference to improvements in concentrate grade and details the metallurgical improvements by replacing column flotation with a Mozley Multi Gravity Separator, as the final stage of cleaning.