Gravimetric Analysis: Substance into Solution
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 […]
Gravimetric Analysis: Precipitation
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, […]
Gravimetric Analysis: Precipitate Filtration
When precipitation is complete the precipitate must be separated from the solution. The means of bringing about this separation will be described under this head. Under the next head (Washing) the completeness of this separation will be considered. Filtering Medium In quantitative gravimetric analysis the two materials generally used are paper and asbestos, and the […]
Assaying of Silver
There has been considerable discussion of late as to the best method of determining the silver-contents of sulphides of silver resulting from the leaching of silver-ores, and also as to the relative merits of the crucible and the scorification method for the determination of the silver-contents of ores. Owing to the great depression in the […]
Working Principles of Jig: Pulsion & Suction
Jig Acceleration Rittinger, having found that jigs save galena of smaller sizes than his formula, worked out in his appendix of the theory of acceleration to account for that fact, showing that a particle of galena which is equal-settling with a particle of quartz reaches its maximum velocity in perhaps one-tenth the time required by […]
Pre-Sizing Jig Feed Classification
The extent to which sizing by sieves should be carried, as a preliminary to the separation, by jigging, of minerals of different specific gravities, has been a matter of controversy for many years. The subject has been investigated by several authorities, yet the ground does not seem to have been completely covered, nor are the […]
Quantitative Analysis Chemistry: GRAVIMETRIC METHODS
In the course of work completed, the problem so far met with has been the determination of the various elements (or compounds) present in a substance. In an ore, for instance, there may be present silica, iron, copper, arsenic, and sulphur, and it is the province of qualitative analysis to determine the presence or absence […]
Analytical Balance
Analytical Balance Principle In this place it will be sufficient to describe the usual chemical balance, designed to carry in each pan a load up to 100 gms. This balance can be obtained at a reasonable figure, and sensitive to 1/10 of a milligram (0.0001 gm.). In the section on Assaying the student will find […]