International Journal of Green and Herbal Chemistry

Transcription

1 IJGC; March 2013 May 2013; Vol.2, No.2, E-ISSN: International Journal of Green and erbal Chemistry Research Article An International Peer Review E-3 Journal of Sciences Available online at Green Chemistry Designing of less azardous and Renewable Substances and Processes Deepshikha Sharma Department of Engineering Chemistry, Jodhpur Institute of Engineering and Technology, Jodhpur, (Raj) India Received: 15 March 2013; Revised: 28 April 2013; Accepted: 11 May 2013 Abstract: Phosphorite, phosphate rock or rock phosphate is a nondetritus sedimentary rock, which contains high amounts of phosphate bearing minerals. The phosphate content of phosphorite is at least 15-20%. The major activity of Rajasthan State Mines and Minerals Limited is the mining of Rock phosphate ore. It operates one of the largest and fully mechanized mines in the country at Jhamarkotra, located in Rajasthan, India. The waste generated at Jhamerkotra requires beneficiation before its utilization by fertilizer industries as a raw material. In the present study the cationic and anionic guar-gums are used for beneficiation process of rock phosphate ore which are to be very useful, efficient and economic. Keywords: Jhamerkotra rock phosphate, beneficiation process, anionic guar gum, cationic guar gum. INTRDUCTIN Green chemistry or sustainable chemistry is a philosophy of chemical engineering that encourages the design of products and processes which minimizes the use and generation of hazardous substances. The definition of green chemistry includes the term hazardous. It is important to note that green chemistry is a way of dealing with risk reduction and pollution prevention by addressing the intrinsic hazards of the substances rather than those circumstances and conditions of their use that might increase their risk. Risk, in its most fundamental terms, is the product of hazard and exposure: Risk = azard X Exposure Bio-degradable polymers and Biological materials- Naturally occurring biopolymers are derived from four broad feedstock areas-(i) Animal sources(ii) Marine sources.(iii)microbial biopolymer feed 275 IJGC; March2013 -May 2013, Vol.2, No.2,

2 stocks (iv)agricultural feed stocks. Starch is an agricultural feedstock hydrocolloid biopolymer found in a variety of plants including wheat, corn, rice, beans and potatoes. Agricultural feed stocks for the biopolymer industry also include fibers that are used as reinforcing fillers. This classification includes cellulose, which is highly polar and considered as biodegradable polymer. 1,2 Guar Gum-India is native of guar or cluster bean. From hundreds of years, Guar has been used as vegetable in India and Pakistan. It is also used as cattle food and as a green manure crop in agriculture. There are various grades of Guar gums pure or derivative. Guar gum is a white to creamy coloured, free flowing powder and free from extraneous matter. Guar gum is a polysaccharide, a long chain made of sugars galactose and mannose.guar gum is a galactomannana similar to locust bean gum consisting of a (14)-linked β-d-mannopyranose backbone with branch points from their 6- positions linked to α-d-galactose (i.e. 16-linked-α-D-galactopyranose). There are between mannose residues for every galactose residue. Chemical structure of guar gum is as follows- C 2 2 C 276 IJGC; March2013 -May 2013, Vol.2, No.2, n C 2 Main guar gum properties are-(i) easy solubility in both hot and cold water (ii) water binding nature due to hydrogen bonding (iii) fine film forming property (iv) resistance to oils, greases and solvents (v) best thickening action (vi) physiologically inert nature (vii) non-ionic, anionic or cationic character. Guar gum is commonly used in Indian homes and its derivatives are globally used in various industries. 3 Need of Rock Phosphate beneficiation-the phosphate fertilizers are in great demand which are now being mostly met through old, less efficient and expansive beneficiation techniques involving high inputs. Sizable amount of P 2 5 values are passing into waste which are spoiling ecosystem and increasing breeding pollution. 4 Role of Guar-Gum and its derivatives in present investigation-present investigation is a step in the direction to develop appropriate technology for recovery of valuable things from waste materials as well as to develop more efficient technology for beneficiation to generate less amount of waste. This innovative method totally eliminated the use of costly phosphoric acid which is used by beneficiation process in Jhamerkotra in high quantity by cheaper and easily available guar-gum and guar-gum based reagents which minimize the production of waste and tailing at their generation stages. Method: In the Present beneficiation process froth flotation technique is used to concentrate the ore. (i) Froth flotation process-the froth flotation utilized the difference in physico-chemical surface properties of the particles of various minerals. After treatment with reagents, such differences in surface properties between the minerals within the flotation pulp become apparent and for flotation to take place an air bubble must be able to attach itself to a particle and fit it to the water surface. In this process the used reagents are-(a) Collector-It collects the valuable particles from the gangue R

3 mineral.(b) Forther -It is used to create froths and to induce the desired froth stability during flotation.(c) Modifiers-p regulators, depressant and activators. Principle-The activity of a mineral surface in relation to flotation reagent in water depends on the forces which operate on that surface. The forces tending to separate particles and bubbles are shown in the following figure. Water Air r w/s r s/a r s/w Solid ere- r w/s =>Surface energy between water/air r s/a =>Surface energy between solid/air r s/w =>Surface energy between solid/water => Contact angle between the mineral surface and the bubble. 5,6 (ii) Present beneficiation technique-present beneficiation technique involves one-step flotation in which phosphate is depressed and carbonates floated out. Silica gangue eliminated by decantation method after conditioning at p 4.0. Flotation process of Jhamerkotra Rock Phosphate for recovery of P 2 5 values using anionic and cationic guar gum Fixed parameters- Feed: (-) 200 meshes, 50gms, 18.56%P25 Sodium leate: 1000gpt Fuel il: 50 gpt Pulp Dencity: 20% I-Anionic Guar-Gum-p=4.0 (acidic)- I-Conditioning period-5mins I I-Conditioning period-15mins Floating Period-5Mins Collector dose Fraction % Grade % Recovery 30gpt Silica tail gpt Froths gpt Tailings gpt Silica tail gpt Froths gpt Tailings gpt Silica tail gpt Froths gpt Tailings IJGC; March2013 -May 2013, Vol.2, No.2,

4 II-Cationic Guar-Gum-p=9.0 (basic)- Collector dose Fraction % Grade % Recovery 30gpt Silica tail gpt Froths gpt Tailings gpt Silica tail gpt Froths gpt Tailings gpt Silica tail gpt Froths gpt Tailings Comparative Study of Parameters- DISCUSSIN AND CNCLUSIN I With collector anionic guar gum at p 4.0 % recovery and % grade of P 2 5 are found maximum % in froths and 32.43% in tailings respectively with 30gpt dose % and 32.11% in tailings respectively with 300gpt dose % and 27.34% in tailings respectively with 3000gpt dose. II With collector cationic guar gum at p 9.0 % recovery and % grade of P 2 5 are found maximum % in froths and 27.06% in tailings respectively with 30gpt dose % and 19.76% in tailings respectively with 300gpt dose % and 19.76% in froths respectively with 3000gpt dose. III The result clearly demonstrated that 300gpt dose of anionic guar-gum at acidic p and 300gpt dose of cationic guar-gum at basic p are most effective. REFERENCES 1. T.M.Aminabhavi, R.. Balundgi, P.E. Cassidy, Review on biodegradable plastics.polymer Plastics Technology and Engineering,1990, 29(3): A.G. Andreopoulos, Degradable plastics: A smart approach to various applications.journal of Elastomers and Plastics. 1994, 24(4): R.Narayan, C. Pettigrew, ASTM standards help define and grow a new biodegradable plastics industry. ASTM Standardization News, 1999, R.Choudhary.& K.P.Deb,Beneficiability of rock phosphate,rsmmly experience 1 its relevance in the Asia context.int.seminar on mini. & minor based Inds. ESCAP region, 1994, 6-9, IJGC; March2013 -May 2013, Vol.2, No.2,

5 5. M.C.Furstnau The metal ion hydrolysis in oxide and silicate flotation M systems,aic. E. Symp.Ser.1973,71, 6. Mining chemicals hand book revised edition mineral dressing notes no-26-1,mci-230-rev.mtc 1989, 867, *Corresponding Author: Deepshikha Sharma; Associate Professor, Department of Engineering Chemistry, Jodhpur Institute of Engineering and Technology, Jodhpur. (Raj) India 279 IJGC; March2013 -May 2013, Vol.2, No.2,