Chemical Beneficiation of Low Grade Coal - A Review

India is having large reserves of low grade coals. The use of low-grade coal in various industries like power plants, metallurgical plants, cement units etc. leads to environ-mental pollution because of generation of large amount of solid and gaseous pollutants. Therefore, it is of impor-tance paramount to clean the coal before its utilization. There are a number of upgrading technologies to produce clean coal. The current paper reviews demineralization aspects by physical and chemical beneficiation of high ash and/ sulfur containing coal.Physical beneficiation of coal is not very effective in separation of the finely dispersed minerals, whereas chemical beneficiation uses expensive reagents and leads to generation of large amount of waste-water which needs to be purified before discharge. Thus, a combined approach consisting of physical and chemical cleaning of coal appears to have a potential for. signifi-cant reduction of ash with less investment while generat-ing less polluting wastewater

Solvent Extraction and Separation of Trivalent Lanthanides Using Cyphos IL 104, a Novel Phosphonium Ionic Liquid as Extractant

Solvent extraction of trivalent lanthanides from chloride solution using a novel ionic liquid Cyphos IL 104 (trihexyl(tetradecyl)phosphonium bis-2,4,4-(trimethylpentyl) phosphinate or [R4PA]) has been investigated, while comparing the results with that of its precursors trihexyl(tetradecyl)phosphonium chloride [R4PCl or Cyphos IL 101], Cyanex 272 [HA] and their equimolar mixture. The results also indicate very high extractability of Cyphos IL 104 toward trivalent lanthanides. Unlike the conventional acidic extractants, extraction of trivalent lanthanides with Cyphos IL 104 increases the equilibrium pH of the aqueous phase due to the preferential extraction of acid over the lanthanide ions. Extraction mechanism has been established by studying the extraction of neodymium(III) with the ionic liquid as a function of the concentrations of Cyphos IL 104 and chloride ions. Separation studies of trivalent lanthanides from a mixed solution containing 1 × 10−4M each of La, Nd, Gd, and Lu with Cyphos IL 104 or Cyanex 272 indicate that Cyphos IL 104 is a better extractant in terms of extraction coefficient, but Cyanex 272 exhibits better selectivity toward heavier lanthanides. The prospects of stripping and regeneration of ionic liquid (Cyphos IL 104) have also been discussed in the present study

Solvent extraction and separation of copper and zinc from a pickling solution

Solvent extraction studies of copper and zinc have been carried out using Versatic 10 acid and Cyanex 272 separately from a model brass pickle liquor. Various parameters for the extraction and separation of copper and zinc such as effect of pH, extractant concentration, phase ratio etc. have been optimized. It was observed that copper was almost completely extracted into the organic phase comprising of 30% Versatic 10 acid at the equilibrium pH of 5.0 using the phase ratio of 1:1 whereas, zinc extraction was noticed at above pH 5.0. On the other hand the pH0.5 values were 3.5 and 4.6 for zinc and copper respectively with 20% Cyanex 272. The difference in pH0.5 value of 1.10 indicated the possible separation of Zn and Cu. By McCabe Thiele diagram number of stages required for the counter current extraction of copper and zinc has been determined for both the solvents. The stripping study showed that 1 mol/L H2SO4 was sufficient to strip metal ions in a single contact from each of the extractant

Processing of a Waste Stream for Separation and Recovery of Copper and Zinc

Solvent extraction studies of copper and zinc have been carried out using Cyanex 272 and LIX 984N separately from a model waste stream of brass pickling. Various parameters for the extraction and separation of copper and zinc such as effect of pH, extractant concentration, phase ratio etc. have been optimized. The results show that extraction of copper and zinc from solution after acid extraction increased with increase in pH and their pH0.5 values were found to be 3.5 and 4.6, and 2.5 and 5.5 with Cyanex 272 and LIX 984N, respectively; LIX 984N showed greater selectivity for copper compared to zinc. By McCabe Thiele diagram number of stages required for the counter current extraction of copper and zinc has been determined for each of the solvents. The stripping study showed that 1 mol/L H2SO4 was sufficient to strip metal ions from both the extractants. An attempt was made to prepare high value products such as copper powder and zinc oxide from the loaded or stripped solution which could be imminently suitable for various P/M and other application

Exact Shannon entropies for the multidimensional harmonic states

In this work we determine and discuss the entropic uncertainty measures of Shannon type for all the discrete stationary states of the multidimensional harmonic systems directly in terms of the states' hyperquantum numbers, the dimensionality and the oscillator strength. We have found that these entropies have a monotonically increasing behavior when both the dimensionality and the population of the states are increasingComment: Accepted and Published in Physica

Isolated fourth ventricle haemorrhage: “think beyond intracranial source’’ unusual presentation of lumbosacral spine arteriovenous malformation presentation

Spinal arteriovenous malformations (SAVMs) are rare vascular lesions and account for about 4% of primary intraspinal masses. Since SAVMs can involve any location along the spinal column and produce a host of different problems, the symptoms are extremely variable. There are few reports of simultaneous cerebral SAH and intraventricular hemorrhage (IVH) following rupture of a spinal AVM (SAVMs). Herein, we present a rare case of Lumbo Sacral spine arteriovenous malformation, which clinically manifests as sudden onset of severe headache and vomiting due to isolated fourth ventricle Hemorrhage (IVH) without cerebral subarachnoid hemorrhage

Extractive separation of La and Nd using Ionic Liquid as extractant

Significant amount of Rare Earth Metals (REMs) are used in magnets, batteries, tube lights, catalyst etc. due to their unique features. Therefore, it is necessary to develop a process which can extract and separate the individual REMs efficiently. The present investigation deals with the solvent extraction and separation of light rare earth elements such as La and Nd from the chloride medium using an ionic liquid(IL), [R3N+.Cy272-] as an extractant. Various parameters were investigated to optimize the condition for separating La(III) and Nd(III) of 10-4M concentration each. At pH 4.0, 90% Nd(III) and 20% La(III) were extracted from the chloride solution. The pH0.5 values for La(III) and Nd(III) were found to be 4.5 and 3.7 respectively. Extraction of La(III) and Nd(III) increased with the increase in IL concentration. At pH 4.5 and IL concentration of 0.01M separation factor (βNd/La) Nd(III) over La(III) was found to be 49. This shows that synthesized ionic liquid has sufficient potential to separate lighter lanthanides (e.g. La and Nd) from their mixed solutions generated during the processing of the REMs from primary or secondary resources

Solvent Extraction of Copper and Zinc From a Pickling Solution Using Versatic 10 Acid, Cyanex 272 and LIX 984N

Solvent extraction studies of copper and zinc have been carried out using Versatic 10 acid, Cyanex 272 and LIX 984N separately from a model brass pickle liquor. Various parameters for the extraction and separation of copper and zinc such as effect of pH, extractant concentration, phase ratio etc. have been optimized. The results show that extraction of copper and zinc from acid free solution increased with increase in pH and their pH0.5 values were found to be 4.0 and 5.6, 3.5 and 4.6, and 2.5 and 5.5 with Versatic 10 acid, Cyanex 272 and LIX 984N, respectively. Versatic 10 acid and LIX 984N shows greater selectivity for copper compared to zinc. By McCabe Thiele diagram, number of stages required for the counter current extraction of copper and zinc has been determined for each of the solvents. The stripping study showed that 1 mol/L H2SO4 was sufficient to strip metal ions in a single contact from each of the extractant

Solvent Extraction and Separation of Copper and Zinc from a Pickling Solution,

Abstract Solvent extraction studies of copper and zinc have been carried out using Versatic 10 acid and Cyanex 272 separately from a model brass pickle liquor. Various parameters for the extraction and separation of copper and zinc such as effect of pH, extractant concentration, phase ratio etc. have been optimized. It was observed that copper was almost completely extracted into the organic phase comprising of 30% Versatic 10 acid at the equilibrium pH of 5.0 using the phase ratio of 1:1 whereas, zinc extraction was noticed at above pH 5.0. On the other hand the pH 0.5 values were 3.5 and 4.6 for zinc and copper respectively with 20% Cyanex 272. The difference in pH 0.5 value of 1.10 indicated the possible separation of Zn and Cu. By McCabe Thiele diagram number of stages required for the counter current extraction of copper and zinc has been determined for both the solvents. The stripping study showed that 1 mol/L H 2 SO 4 was sufficient to strip metal ions in a single contact from each of the extractant