Ammoniacal Carbonate Leaching: Effect of Dissolved Sulfur in the Distillation Operation

The distillation process in the Ammoniacal Carbonate Leaching technology was studied at bench-scale and on industrial scale. The dissolved sulfur effect in the Product-liquor that feeds to the columns, on the Basic Nickel Carbonate (BNC) properties and the operation expenses was determined. When increasing the sulfur in the liquor, we augment the selectivity towards the sulfate formation in the BNC molecule; therefore the energy consumption to the BNC thermal decomposition in the calcination process increases. Also, the nickel dissolved in the columns effluent increases due to complex reaction with [SO42–] and [S2O32–] ions, thus the expenses for consumption precipitation reagent increase too. Feeding carbonated liquor in the range 1.60 ≤ NH3/CO2 < 1.80 and CO2-rich solution increases the CO2 in the BNC with decreasing in sulfate; then, the mean diameter particle increases, the filtration resistance and the cake moisture diminish, which augments the productivity and reduces the energy consumption in the process of filtration and calcination. Keeping a pH between 8.4 and 8.7 in the columns outlet the greatest economic benefit is obtained of 0,125 ($ · h–1) per (m3 · h–1) of Product-liquor.

Removal of Phosphorus from High-Phosphorus Manganese Ores by Ammonia-Ammonium Carbonate Leaching Method

High-phosphorus manganese ores provide an important source of manganese, which is regarded as an irreplaceable material in the steel industry. The ammonia-ammonium carbonate leaching method was proposed for the removal of phosphorus and extracting manganese from high-phosphorus manganese ore, both effectively and environmentally. To explore the dissolution behavior of phosphorus and manganese in the ammonia-ammonium carbonate solution, the effect of the ammonia-to-ammonium carbonate concentration ratio, the leaching temperature, and the liquid-to-solid ratio on manganese extraction and dephosphorization rate were investigated. In addition, the composition of precipitated manganiferous sample, which was obtained from high-phosphorus manganese ores by ammonia-ammonium carbonate leaching process, was also studied. The results indicated that more than 99.2% phosphorus was removed and more than 83.5% of manganese was extracted by ammonia-ammonium carbonate leaching under the following conditions: ammonia to ammonium carbonate concentrations: 14:2 mol/L; liquid/solid ratio: 5:1 mL/g; leaching temperature: 25 °C; The precipitated manganiferous sample has little impurities, Mn% is 44.12%, P% is 0.02%, P/Mn = 0.00045.