The products test according to the application, different test criteria need to be selected. We can refer to national standards, industry standards and international standards for testing. For example, barite for export as a drilling mud aggravating agent can usually be tested with reference to API standards and ISO standards. Conventional test items include density, water-soluble, cadmium, 75 μm sieve residue, and so on.
Density is a very important indicator of the density of barite directly related to its price. Therefore, how to test and calculate the density of barite is very important.
The density of the barite is usually measured using a Lee density bottle. The mass of the barite is measured with a balance, denoted as M. In the Lee density bottle filled with kerosene, write down the scale V1. Put the barite into, write down the scale V2, and finally by the density formula P = M / V, the M divided by V2-V1, calculate the density.
The content of cadmium is the main content of barite test
Determination of cadmium content in barite─Atomic Absorption Spectrometry Method.
Standard specification for determination of cadmium in barite by atomic absorption Spectrometric method, and it is also applied to the determination of cadmium content in barite, the range is 0.000 04%~0.001 8%.There are papers that GB/T6682 Laboratory water specifications and test methods and Calibration procedure for JJG694 Atomic Absorption spectrometer
After digestion and treatment of the specimen, the atomic absorption spectrophotometer is imported into a 228.8nm resonant line, and the absorption value is proportional to the cadmium content in a certain concentration range, and the cadmium content is determined by comparing it with the Cadmium standard series.
Weighing the 5g specimen (precise to 0.001g) in a 200mL beaker, with a small amount of water wetting, adding 15mL Aqua regia (4.4), with glass rods stir and cover the surface dish, carefully heated dissolved in the electrothermal plate, near dry. Removing the beaker from cooling to room temperature and transferring to the 100mL capacity bottle containing 2mL nitric acid (4.5), dilute to the scale, and then filter to the solution clarification, to be tested.
Removing 0.0mL, 0.25mL,0.5mL, 1mL, 2mL cadmium standard working fluid (4.9) is placed in a group of 100mL capacity bottles containing 5mL nitric acid (4.5), diluted with water to scale, shake evenly. This solution contains cadmium per ml of 0.00 μ g,0.025 μ g, 0.05 μ g,0.10 μ g,0.20 μ g respectively.
The Blank solution, the cadmium standard solution, is measured by the atomic absorption spectrophotometer respectively. At the wavelength of 228.8nm, the absorbance is measured separately, and the cadmium content is calculated by comparing the arbitrary content of cadmium standard and corresponding absorbing light.