Zinc occurs in nature most commonly as sulphide (blende); it also occurs as carbonate (calamine) and silicate (smithsonite). Each of these is sufficiently abundant to be a source of the metal. The metal is known in commerce as “ spelter ” when in ingots, and as sheet zinc when rolled. It is chiefly used in … Read more
Occurs less abundantly than nickel. Its chief ores are smaltite and cobaltite, which are arsenides of cobalt, with more or less iron, nickel, and copper. It also occurs as arseniate in erythrine, and as oxide in asbolan or earthy cobalt, which is essentially a wad carrying cobalt. It is mainly used in the manufacture of … Read more
Titanium only occurs as a mineral in its oxidised state, or as titanic oxide (TiO2). It is a substance which has little commercial value, and is generally recognised as one of the rare bodies; although, in small quantities, it is widely disseminated. It occurs in granite, basalt, and other igneous rocks in quantities up to … Read more
The ammonic carbonate filtrate from the silica is evaporated to dryness, ignited strongly over the blowpipe, and weighed. The residue is tungstic acid, WO3. The tungsten may be conveniently reported in this form, although it is probably present as a lower oxide. The acid filtrate from the silica and tungstic acid is treated with sulphuretted … Read more
QUALITATIVE DETECTION Because of the distinctive colors of the precipitates formed, various cations have been proposed for the qualitative detection of the ferrocyanide ion. Since interference frequently occurs, some care is usually necessary. As an illustration, the following condensed procedure serves for the detection of the ferrocyanide ion in the presence of ferricyanide and thiocyanate: … Read more
The Metallurgical pilot concentration plant is completely equipped with gravity and flotation units sufficient to provide for practically any flowsheet employing these methods of concentration. All equipment for the pilot concentration plant is set for continuous operation. Due to movable launders, pumps, and flow pipes, extreme flexibility is available. Crushing: Ore is prepared in the crushing, … Read more
The conditions essential to accurate gravimetric analysis have been given. As a rule such estimations come under one of four classes: Direct Estimations These are the most usual and accurate methods of gravimetric analysis. The element sought is precipitated and weighed generally as a compound, definite in composition. Direct Estimation by Loss Here the element … Read more
WASHING THE PRECIPITATE: A precipitate may be washed directly on the filter, or it may be washed partly by decantation and partly on the filter. If by decantation, the precipitate is allowed to settle, and the supernatant liquid is poured on the filter. Wash water is added to the precipitate, and after settling, the decantation is … Read more
Material of Vessels for Solution The student must consider the effect of the solvent used on the vessel. In most cases the solvent used is an acid or mixture of acids, and for such solvents glass and porcelain are generally used. Platinum may be used, provided no chlorine or other attacking agent be present. (See … Read more
After solution, certain minor operations may or may not be necessary, but as a rule the next essential operation is that of precipitation. In his qualitative work the student has already come across many cases of precipitation, and he will find that many of the methods there used are again applied for quantitative purposes. Silver, … Read more