Titanium dioxide, which is the most common white pigment in paint, can be produced from the titanium mineral, rutile, by chlorination to TiCl4, followed by oxidation to TiO2. To purify the insoluble titanium dioxide, it is washed free of soluble impurities in a continuous, countercurrent system of thickeners with water.  Two hundred thousand kg/h of 99.9 wt% titanium dioxide pigment is to be produced by washing, followed by filtering and drying.  The feed contains 50 wt% TiO2, 20 wt% soluble salts and 30 wt% water.  The wash liquid is pure water at a flow rate equal to that of the feed on a mass flow basis.

Alumina from bauxite separation stage calculations A crucial step in the production of aluminum from bauxite ore is the separation of alumina from the remaining mineral impurities in the ore. In the Bayer process this is accomplished by treating bauxite with aqueous NaOH to produce NaAIO2 (alumina). NaOH(aq) + Al(OH)3(s) → NaAIO2(aq) + 2H2O(1) Since NaAIO2 is water soluble while the residual mineral constituents of bauxite are not, a separation can be achieved by allowing the minerals to settle out and decanting the aqueous solution of NAAIO2 and unreacted NaOH. In order to further recover any NAAIO2 entrained in the settled mineral solids, this "mud" is repeatedly washed with water and allowed to settle, and the wash water is decanted. The figure below shows one stage of this washing-settling process. Wash water Slurry - Open to air Mixer/Wash tank Setling tank Decanted solution System boundary Washed mud In this stage, a feed slurry consisting of 10 wt% solids, 11 wt% NaOH, 16 wt%…

Potassium fluotitanate (K₂TiF₆), a starting material forproducing other titanium salts, is made by dissolvingtitanium(IV) oxide in concentrated HF, adding aqueous KF, andthen heating to dryness to drive off excess HF. The impure solidis recrystallized by dissolving in hot water and then cooling to 0°C, which leaves excess KF in solution. For the reaction of 5.00 g of TiO₂, 250. mL of hot water is used to recrystallize theproduct. How many grams of purified K₂TiF₆ are obtained?(Solubility of K₂TiF₆ in water at 0°C is 0.60 g/100)

Portland Cement is manufactured by the dry process conforming to the following specifications: Lime Saturation Ratio: - (CaO +1.5 Mg0 - 0.7 SO3)100 2.85 SiO₂ + 1.18Al2O3 + 0.65 Fe₂03 92 Iron Ratio = Al₂O3 = 2 Fe₂03 Magnesia, MgO should not exceed 1.5% and Sulfur as SO3 is 2.2% by wt Silica content of 24% by wt is acceptable The above cement is manufactured in a rotary kiln using limestone and clay as raw materials mixed in 75:25 proportion by weight. Analysis of Raw Materials Component Limestone,% Clay, % CaO 54.5 7.13 Fe₂O3 0.42 7.68 Al₂O3 0.83 17.15 SiO₂ 1.72 55.14 MgO 0.85 2.16 CO₂ 41.68 10.74 100 100 In the kiln, coal is added to supply heat of combustion. Coal contains 67.2%C, 4% H, 1.7% S, 2.2% 0, 2.6% H₂O and 22.3% ash. Its gross calorific value is 25.62 MJ/kg on a dry ash-free basis. Air supplied is 10% in excess at 27°C, 100 kPa and 75% RH. The stack gas contains 23.5% CO₂. The clinker is cooled and gypsum (essentially pure CaSO4) amounting to 3% its mass is added. The final…

4. At 1084 °C solid copper melts to form a liquid. The phase change can be described as Cu(s) → Cu(t). The density of solid and liquid copper are 8.96 g/cm' and 7.75 g/cm' respectively. The enthalpies of combustion of the solid and liquid are -156.06 kJ/mol and -167.92 kJ/mol respectively. The product of combustion of both the solid and liquid is CuO(s). Calculate the standard enthalpy changes for the fusion process in kJ/mol. Calculate the change in internal energy when the sample is under a pressure of 500 kbar. Cu(s) → Cu(e) Solid copper liquid copper enthalples of combustion 8.96 g/cm3 7.75 g 1cm² said: -156.06 kJ/mol liquid-162.42 kJ/mol