Processing of Beach Sand Minerals of Maharastra Coast

In the present paper, an attempt has been to bene-ficiate beach sand minerals of Maharastra coast. For this purpose, beach sand mineral samples were collected from two different coastal places namely; Pirawadi and Kother-wadi area. The samples obtained were subjected for chara-cterization & beneficiation studies. The characterization studies were mainly carried out by mineralogical analyses. The mineralogical analyses indicated 12-15% Ilmenite, 5-7% Magnetite and 65-70% Quartz in Pirawadi sample. Similarly Kotherwadi sample showed the presence of 10-12% Ilmanite along with 40-45% quartz. The studies also indicated the increased heavy mineral concentration in finer size (-75 11) fractions. Further, the beneficiation studies were carried out using Perm roll magnetic separator using different variables such as particle size, magnetic inte-nsity, roll speed, splitter position etc. From the studies it was possible to recover 80-85% magnetic minerals under different conditions

Recovery of monazite from red sediments of badlands topography of south east coast of India and its characterization for industrial applications

1528-1535An attempt has been made in this paper to recover pure monazite, a source for thorium, from the red sediments badlands topography of Kalipalli village of Ganjam district of Odisha, India by developing an industrially viable process flow sheet from a feed sample containing monazite mineral 0.63 % by weight. Results have indicated that monazite purity of 98 % could be achieved with a recovery of 63 % by weight. Recovery of monazite can be enhanced if the spiral concentrate is further scrubbed in alkaline media prior to subjecting to mineral separation studies. In the present investigation an attempt is also made to compare the monazite occurring from red sediment sample with naturally occurring monazite from beach sands. It is found that in spite, their morphological and topographical characteristics are markedly different the monazite occurring from both sources, have chemical elemental similarity. It is also seen that the chemical states of rare earth (RE) elements in monazite of both sources are matching. Further, due to natural occurrence of finer particle size of monazite (< 150 micron) in red sediments sample, the material is found to be suitable for chemical treatment to recover easily the valuable rare earths from it. Hence, it is recommended for mining of red sediments for recovery of monazite from red sediments of badlands topography as an additional resource for beach sand monazite

Amylopectin grafted with poly (acrylic acid): Development and application of a high performance flocculant

In recent years, wastewater treatment, especially for wastewaters which are not suitably recycled by conventional or normal biological processes, is getting more importance. Of late, natural biopolymer based flocculants are extensively used for wastewater treatment because of low cost, environment-friendly and easily availablility from reproducible farm and forest resources. This article introduces the development of a natural polymer based flocculant [amylopectin grafted with poly (acrylic acid) - AP-g-PAA] for treatment of synthetic effluent as well as mining industry wastewater. The graft copolymer based flocculants have been developed under optimum conditions and characterized using viscometry, C-13 NMR, SEM, TGA, rheological characteristics, determination of hydrodynamic radius and CHN analysis. The flocculation characteristics of grafted and ungrafted polysaccharide have been evaluated in synthetic effluents (as Fe-ore, kaolin, Mn ore suspensions) as well as in mining industry wastewater. (C) 2013 Elsevier Ltd. All rights reserved

Transcriptional Activation of OsDERF1 in OsERF3 and OsAP2-39 Negatively Modulates Ethylene Synthesis and Drought Tolerance in Rice

The phytohormone ethylene is a key signaling molecule that regulates a variety of developmental processes and stress responses in plants. Transcriptional modulation is a pivotal process controlling ethylene synthesis, which further triggers the expression of stress-related genes and plant adaptation to stresses; however, it is unclear how this process is transcriptionally modulated in rice. In the present research, we report the transcriptional regulation of a novel rice ethylene response factor (ERF) in ethylene synthesis and drought tolerance. Through analysis of transcriptional data, one of the drought-responsive ERF genes, OsDERF1, was identified for its activation in response to drought, ethylene and abscisic acid. Transgenic plants overexpressing OsDERF1 (OE) led to reduced tolerance to drought stress in rice at seedling stage, while knockdown of OsDERF1 (RI) expression conferred enhanced tolerance at seedling and tillering stages. This regulation was supported by negative modulation in osmotic adjustment response. To elucidate the molecular basis of drought tolerance, we identified the target genes of OsDERF1 using the Affymetrix GeneChip, including the activation of cluster stress-related negative regulators such as ERF repressors. Biochemical and molecular approaches showed that OsDERF1 at least directly interacted with the GCC box in the promoters of ERF repressors OsERF3 and OsAP2-39. Further investigations showed that OE seedlings had reduced expression (while RI lines showed enhanced expression) of ethylene synthesis genes, thereby resulting in changes in ethylene production. Moreover, overexpression of OsERF3/OsAP2-39 suppressed ethylene synthesis. In addition, application of ACC recovered the drought-sensitive phenotype in the lines overexpressing OsERF3, showing that ethylene production contributed to drought response in rice. Thus our data reveal that a novel ERF transcriptional cascade modulates drought response through controlling the ethylene synthesis, deepening our understanding of the regulation of ERF proteins in ethylene related drought response

Selective flocculation of low grade iron ore slimes using different types of polymers

A study on selective flocculation of low grade iron ore slimes employing carboxymethyl cellulose (CMC) and starch as flocculants and sodiumhexameta phosphate (SHMP) as dispersant has been carried out. The mineralogical studies reveal that the presence of hematite and goethite as major iron bearing phase. Quartz and kaolinite are found to be gangue minerals. The experiments carried out indicate that the Fe grade is enhanced from 58.24% to 65.32% Fe using starch as flocculant. A Fe grade of 63.44% is obtained using CMC as flocculant. Further, the efficacy of the studies was analysed using separation index, which indicate that the higher separation index was obtained with the tests employing starch

Selective flocculation of low grade iron ore slimes using different types of polymers

411-416A study on selective flocculation of low grade iron ore slimes employing carboxymethyl cellulose (CMC) and starch as flocculants and sodiumhexameta phosphate (SHMP) as dispersant has been carried out. The mineralogical studies reveal that the presence of hematite and goethite as major iron bearing phase. Quartz and kaolinite are found to be gangue minerals. The experiments carried out indicate that the Fe grade is enhanced from 58.24% to 65.32% Fe using starch as flocculant. A Fe grade of 63.44% is obtained using CMC as flocculant. Further, the efficacy of the studies was analysed using separation index, which indicate that the higher separation index was obtained with the tests employing starch

Environmental aspects of bacterial oxidation with respect to the mining and processing of some sulfide minerals

The acid production potential of sulfide-containing ore and tailing samples from Au and Cu mining in the state of Karnataka, India, depended essentially on their mineralogical characteristics and the amount of S present in the samples. The acid-buffering capacities of the materials were in order: Cu tailings &#62; Au tailings &#62; Cu ore (+100 mesh) &#62; Cu ore (+60 mesh) &#62; Cu ore (+44 mesh) &#62; Cu ore (+10 mesh). Thiobacillus ferrooxidans Enhanced acid production and heavy metal ion dissolution; bacterial oxidation is influenced by pH, sulfide minerals present, etc. High pH levels and a bactericide retarded bacterial oxidation

Selective flocculation of sulfides with reference to environmental control

An assessment of the use of high-mol.-wt. polymers such as polyacrylamide, cellulose xanthate, and starch xanthate in the selective flocculation of sulfides from oxide gangue was made from an environmental viewpoint. Role of the functional groups in the polymers and of operating variables such as conditioning time and desliming was examd. Studies were made on chalcopyrite-quartz and pyrite-quartz mixts. in the presence of the polymers

Sustainable Use of Copper Resources: Beneficiation of Low-Grade Copper Ores

The global market has announced copper as a modern energy metal and finds its extensive utilization in the construction industry, electrical wiring, power transmission lines, alloying, anticorrosive coating, heat exchangers, refrigeration tubing, etc. Copper ore is primarily beneficiated from sulphide mineral deposits. Due to high-grade copper sulphide deposit exhaustion, the focus has now shifted towards recovery from different lean-grade oxide and mixed ore deposits. The present paper summarizes the utilization of copper as a clean energy mineral and its importance in the current renewable energy sector. Extensive research has been carried out on the flotation of copper sulphide ore as compared to copper oxide and mixed type ores. Besides flotation, other beneficiation techniques (selective flocculation and gravity separation) are also discussed in the present review. A few novel pretreatment methods are currently being studied for copper ore to intensify the separation for higher productivity