Effect of Acid Leaching on Recovery of Graphite from Calcareous Deposits

In this paper an attempt has been made for optimisation of acid leaching of calcite from graphite ore of Tamilnadu. The ore containing 39% acid soluble and 61 % insolubles. The best leaching parameters obtained at particle size below 150 microns are reaction time 20 minutes,temperature 40°C, solid liquid ratio 1:4 and stoichiometric ratio of acid 0.69. Flotation test results on partial leached and on unleached sample indicate that the graphite grade and recoveries are improved from a calcite leached sample. The flotation product obtained from a leached sample contains 73% fixed carbon with 83% recovery

Influence of the Static Screen Inclination on the Effect-ive Separating Size and Concentration of Beach Sand Minerals

In this paper an attempt has been made to evaluate the effect of inclination of micro screen on the effective separating size of beach sand minerals. The results of these investigations indicate that the cut sizes of 130pm, 122pm, 63pm, 55pm and 40pm could be obtained from a feed containing —1mm size range with a variable deck inclina-tion such as 35°, 40°, 67°, 70° and 75° respectively. The cut sizes are evaluated based on the partition curve according to Tromp. The typical size analysis data obtained at cut size of 63pm, indicate that the overflow and +300pm size fraction of the under flow contain rejec-table tailings amounting to 51% by weight with overall heavies loss contain 4.7%, Thus micro screen is effective for dual purpose such as classifications like hydrocyclone and preconcentration like a spiral concentrator. Hence, it can be concluded that the micro screen is not only an effective for classification at different cut points but also can work as a good preconcentrator for beach sands

Flotation Kinetics of Coking Coal Fines

Investigations were carried out on the coking coal fines generated at Bhelatand Washery. The studies include inve-stigations on physical, chemical and flotation chara-cteristics. Different operating parameters were optimised in flotation to get best product with low ash content. Flotation performance was evaluated by studying the kinetics of different size fractions and also on sample ground for different length of time. Flotation rate constant was calculated using Klimpei's model. Maximum Rate constants were obtained for size fraction -300+150μm (-0.0082)and one minute ground product (-0.0077) with low ash content. From these observations it is concluded that less than one minute grinding is sufficient for these coal fines to achieve a better product with minimum sh

Beneficiation studies on beach placer sample for steel making industries

Beneficiation studies were carried out on the Talashil beach placer sample of South Maharastra Coast, India. The sample contains magnetite, ilmenite, rutile, hematite, goethite and chromite as opaque minerals in the sample. The total heavy minerals fraction reaches 53.8 % by weight whereas the total magnetic minerals are 56.9%. It is observed that the 2nd stage DHIMS magnetic fraction contains 65.2 % Fe2O3 with an over all yield of 37.8 % and a 86 % recovery from a containing 26.8 % Fe2O3 feed. This product can be used in the pellet feed for steel making after suitable blending with high-grade iron ore fines

Characterisation and Response to Beneficiation of Ferruginous Chromite Ores

Sukinda-Nausahi belt of Orissa, represent about 90% of the Indian Chromite ore reserves. These ores are later-itic type in nature resulted by weathering of ultrabasic rocks, Metallurgical industries consume maximum chromite ores- around 50% followed by refractory and chemical indu-stries which consume about 35% and 15% respectively. The utility pattern of chromite in industries is varying greatly. The variation in the demand could be due to lim-ited market for medium and low grade chromite. Hence it is necessary to improve the chromium content for better util-isation and conservation of available resources

Jenis, Harga Kayu Komersil Dan Analisis Ekonomi Pada Industri Kayu Sekunder (Panglong) Di Kabupaten Karo (

This research aimed to determine the type and price of commercial timber traded in Karo district. This research investigated the secondary wood industry usually called “panglong” as an object as well as the source of information. This research was conducted by the observation to secondary wood industry in 17 districts of Karo. Data include the type, size, and price of wood, then data was tabulated. Then, the economic analysis for secondary industry wood was performed. The analysis results of 17 from industry surveyed in Karo district showed that the type of wood being traded were dominated by any kind of hard wood with percentage of 100%, pine (Pinus merkusii) of 88.23%, any hard woods of 76.47%, and meranti (Shorea sp) and dammar (Shorea macroptera) of 23.52%. Pine has the cheapest price among the commercial timber species that are traded others. Traded timber prices ranging from Rp. 10000 to Rp 11000 per inch. The greater secondary wood sawmill is UD. Surbakti with 25 employees and the BEP value of door frame production are Rp. 572625/ product, window sills Rp. 574875/product, while the smallest is UD. Mual Nauli with 2 employees and BEP value of window sills are Rp 250000 / product and ventilation Rp 62500 / product

Characterisation and Liberation of Graphite Schist

This paper deals with the characterisation and liberation studies of graphite schist from Shivaganga, Tamilnadu. The graphite flakes are interbanded with quartz and calcite. Secondary calcite veins often traverses graphite flakes and quartz grains. Based on grain counting, frequency curves , comminution followed by flotation tests , the liberation size of graphite is estimated between 150to 90 microns. Therougher concentrate achieved at d&, passing of 145 micron size product contain 35 % FC with 99% recovery.The SFM study reveals the presence of minute inclusions of calcite and quartz within graphite flakes