NOPR Collection:

Effect of rectangularity on compressive strength of coal pillar

2016-07-20T06:45:06Z

Title: Effect of rectangularity on compressive strength of coal pillar Authors: Shrivastva, B K; Singh, C S; Dhar, B B Abstract: Compressive strength of coal pillar is dependent on various factors like environment, shape and size. This paper deals with the effect of rectangularity on the compressive strength of coal pillars. Tests of rectangular coal specimens have been done in the laboratory under controlled loading conditions. The volume and height of the coal specimens have been kept constant and rectangularity has been varied. It has been found that the strength of coal specimens decreases with increasing rectangularity. A relationship has been established to find the strength of rectangular coal pillars. Page(s): 145-146

Studies on energetic compounds Part 9: Preparation and thermal decomposition of 1- and 2-naphthylammonium nitrates and perchlorates

2016-07-20T06:45:06Z

Title: Studies on energetic compounds Part 9: Preparation and thermal decomposition of 1- and 2-naphthylammonium nitrates and perchlorates Authors: Singh, Gurdip; Kapoor, Inder Pal Singh; Jacob, Smiju Abstract: 1- and 2-naphthylammonium nitrates and perchlorates have been prepared and characterized. Thermal and explosive characteristics of these salts are studied by TG, DSC and ignition delay measurements. Suitable decomposition pathways have also been proposed. Page(s): 140-144

Admixed binders and lubricants in ceramic powder pressing-A study of zinc behenate additive

2016-07-20T06:45:05Z

Title: Admixed binders and lubricants in ceramic powder pressing-A study of zinc behenate additive Authors: Balakrishna, Palanki; Murty, B Narasimha; Yadav, R B; Anuradha, M; Narayanan, P S A; Pramanik, R; Majumdar, S Abstract: Admixed lubricants are used to bring down compaction and ejection pressures, and to increase packing efficiency in ceramic powder pressing. Admixed binders are used for increasing green strength of the compact. The stronger and denser green compacts so obtained, sinter to high densities without defects and with minimal shrinkage, leading to very high acceptance rates in large scale production. Zinc behenate powder has been used as a lubricant cum binder for uranium dioxide with very good results. Green density versus compaction pressure has been obtained. Weight loss with temperature of free and admixed zinc behenate and carbon and zinc loss in admixed compact and other data are presented. On the other hand, the use of zinc behenate could lead to bloating and high nitrogen values in sintered uranium dioxide under some conditions of processing, which have been identified. Page(s): 136-139

Magnetic-gravity separation of iron ore

2016-07-20T06:45:01Z

Title: Magnetic-gravity separation of iron ore Authors: Usachyov, P A; Korytny, S Yu Abstract: In order to produce high-grade iron ore concentrates a magnetic-gravity method has been developed for separation of magnetite ore. It provides separation of mineral complexes according to magnetic properties, density and size. Magnetic-gravity separators (MGS) have been designed and their parameters are defined, It has been shown that MGS enables to obtain 1.5-3.0% improvement in Fe content in concentrates and to produce super concentrate (72% Fe, 0.2-0.3% SiO₂). MGS also provides for intensification of thickening and desliming of ferromagnetic suspensions. Page(s): 130-135