Coal ash utilization in building and agricultural applications

The increasing cause of disposal of coal ash in terms of environmental pollution stresses the urgent need to find its potential uses. In order to use coal ash fruitfully, various experiments have been carried out at RRL, Bhopal in making concrete block, brick, door shutters, etc. But these hardly consume about 5% of the total quantum of ash produced annually in India.Therefore, attempts have been made to utilise the coal ash in bulk quantity for conditioning wasteland, to increase its fertility Coal ash is basically an amorphous ferro-alumino silicate, which is also characteristically high in Ca'+ Mg++ Na' and K+. The impact of coal ash in agriculture and in building application depends on various physico-chemical properties for which multi -disciplinary experiments have been conducted at lab scale in RRL, Bhopal and optimized the process details for pilot scale demonstration. This paper deals with the use of coal ash in agriculture and the process of making construction materials and its properties. Crops, vegetables and cereals had grown and were found that the crop yield increased by coal ash application and there was no toxicity. Coal ashes have been used as filler and natural fibre jute as reinforcement in making polymer composite,which can be used as wood substitute materials. Coal ash addition increased the dimensional stability; hardness, durability, and wear resistance

Recycling marble wastes and Jarosite wastes into sustainable hybrid composite materials and validation through Response Surface Methodology

During marble processing such as cutting, polishing and grinding, a considerable amount of fine residues refereed as marble processing rejects (MPRs) are produced and have become a serious environmental issue. So the current study deals with the conversion of MPRs into hybrid ceramic composite bricks (CCB) with Jarosite waste in a clay matrix system. Mix design and optimization of CCB was performed to illustrate the potentials of MPRs and Jarosite wastes as low-cost high-value composites materials. Response Surface Methodology (RSM) model was also used in this work for simulation and to optimize the process for improving CCB quality employing classic mixture approach. Detoxification through mineralogical changes was achieved during firing composite bricks at 960 °C ± 2 °C and was confirmed using the XRD analysis. Compressive strength of CCB using 15% MPRs with 1:1 Jarosite waste - clay matrix ratio met the standard quality (>35 kg/cm2) for its use in construction purpose. It is evident from the RSM model results and statistical analysis for the response compressive strength, shrinkage, water absorption capacity, density and leachate concentration of Cd as well as Pb in the CCB is in laudable agreement with actual experimental performance

Preparation and characterization of penta alkyds based on mahua oil.

A medium oil length alkyd resin is prepared from mahua oil (a non-traditional oil), pentaerythritol and phthalic anhydride. The alkyd was characterized by IR analysis. Other properties viz. , viscosity, specific gravity, acid number, saponification value etc. were determined. Film characteristics of the resin like drying time, thickness, scratch hardness, impact resistance and adhesion were also assessed. The performance of the resin was found to be comparable to a commercial resin. Penta alkyd developed using mahua is of non-drying nature. It can be used as a baking system by curing with melamine at 140oC for 4 hr. The baked film offers good mechanical properties as well as resistance to water and alkali. Combination of ester gum with mahua alkyd gives an air dying resin

Protection of bamboo surfaces by CNSL based coatings

145-149<span style="font-size:11.0pt;line-height:115%; font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" "dejavu="" sans";mso-hansi-theme-font:minor-latin;mso-bidi-font-family:mangal;="" mso-bidi-theme-font:minor-bidi;color:#00000a;mso-ansi-language:en-us;="" mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">Surface coatings based on CNSL were prepared from formaldehyde, styrene, hexamine and epichlorohydrin for the protection of bamboo surfaces. CNSL based coatings were applied on bamboo and the performance of these coatings was evaluated by accelerated and chemical resistance tests. It was observed that these coatings can be used for the protection of bamboo from corrosive environments.</span

Utilization and value addition of copper tailing as an extender for developent of paints.

The present study deals with characterization of copper tailing waste, test for possibilities of hazards and its potential reuse as an extender in paints. The waste is a siliceous material containing aluminum oxide, iron oxide and sulphate in significant concentrations. In the primary stage waste is acidic in nature, which makes it unsuitable for paint. This acidity is removed from the waste by simple sieving and grinding. The prepared mass was characterized for basic properties of an extender like oil absorption, specific gravity, pH, etc. Toxicity studies were also conducted in term of leaching of heavy metals by standard techniques (USEPA using TCLP). Properties of the prepared paint's film in terms of hardness, adhesion, resistance to abrasion, resistance to impact, resistance to corrosion (under humidity and salt fog), etc. were evaluated and compared with a similar formulation of conventional extender and found satisfactory. Results from the experiments indicated that developed extender is environmentally clean and cost-effective

Jarosite characteristics and its utilisation potentials.

During metallic zinc extraction from zinc sulphide or sulphide ore, huge quantity of jarosite is being released universally as solid residues. The jarosite mainly contains iron, sulphur, zinc, calcium, lead, cadmium and aluminium. Jarosite released from such industrial process is complex and its quality and quantity make the task more complex for safe disposal. Apart from water contamination, jarosite already accumulated and its increasing annual production is a major source of pollution for surrounding environment including soil, vegetation and aquatic life and hence its disposal leads to major concern because of the stringent environmental protection regulations. An attempt was made to evaluate the characteristics of Indian jarosite with an objectives to understand its potentials for recycling and utilising as raw materials for developing value added products. Sand and Coal Combustion Residues (CCRs) was used as an admixture to attain good workability and detoxify the toxic substance in the jarosite. Result revealed that jarosite is silty clay loam in texture having 63.48% silt sized and 32.35% clay sized particles. The particle size of jarosite (D90=16.21F0.20 Am) is finer than the CCRs (D90=19.72F0.18 Am). The jarosite is nonuniform in structure and shape as compared to the CCRs having spherical, hollow shaped and some of them are cenosphere in nature. The major mineral phase of jarosite is Potassium Iron Sulphate Hydroxide {KFe3(SO4)2(OH)6}and Iron Sulphate Hydrate {2Fe2O3SO3d 5H2O}. In CCRs the dominant phases are quartz {SiO2}, mullite {3Al2O3d 2SiO2} and hematite {Fe2O3}. The high electrical conductivity of jarosite (13.26F0.437 dS/m) indicates that the presence of cations and anions are predominant over CCRs (0.498F0.007 dS/m). The major portion of jarosite consists of iron (23.66F0.18%), sulphur (12.23F0.2%) and zinc (8.243F0.075%). But CCRs main constituents are silicon ( 27.41F0.74%), aluminium (15.167F0.376%) and iron (4.447F0.69%). The other constituents such as calcium, aluminium, silicon, lead, and manganese are also present in the range of 0.5 to 5%. Heavy metals such as copper, chromium, and cadmium are found higher in jarosite as compared to the CCRs. The statistically designed experimental trials revealed that the density, water absorption capacity and compressive strength of fired jarosite bricks are 1.51 gm/cm3, 17.46% and 43.4 kg/cm2 respectively with jarosite sand mixture in the ratio of 3:1 indicating the potentials in developing building material

Allelopathic effect of Parthenium hysterophorus on the chlorophyll, nitrogen, protein and ascorbic acid content of lantana camara.

\ud \ud \ud Alleopathic effects of parthenium hysterophorus on the chlorophyll, Nitrogen, Protein and ascorbic acid \ud content of Lantana Camara Alleopathy Journal \ud 15 (2):305-310 \ud \ud (2005), 0.68