BS EN 12912:2012 pdf download – Products used for treatment of water intended for human consumption — Barite
5.3.2 Bulk density packed
The bulk density packed shall be in the range of 2 500 kg/m 3 to 2 600 kg/m 3 .
6 Chemical properties
This European Standard specifies the minimum purity requirements for barite used for the treatment of water intended for human consumption. Limits are given for impurities commonly present in the product. Depending on the raw material and the manufacturing process other impurities may be present and, if so, this shall be notified to the user and when necessary to relevant authorities. Users of this product should check the national regulations in order to clarify whether it is of appropriate purity for treatment of water intended for human consumption, taking into account raw water quality, contents of other impurities and additives used in the products not stated in this product standard.
Limits have been given for impurities and chemical parameters where these are likely to be present in significant quantities from the current production process and raw materials.
If the production process or raw materials lead to significant quantities of impurities, by-products or additives being present, this shall be notified to the user. The composition of the commercial product shall conform to the requirements specified in Table 1.
After filling, washing and commissioning of a filter system producing drinking water, barite should not increase the concentrations of chemical parameters (see [1]). NOTE Water extractable substances, determined in accordance with the method for granular materials given in EN 12902, can be used to estimate the leaching of the chemicals specified in EN 12902.
7 Test methods
7.1 Sampling
Prepare the laboratory sample(s) required by the relevant procedures described in EN 12902.
7.2 Analysis
7.2.1 Particle size distribution
The particle size distribution shall be determined in accordance with EN 12902.
7.2.2 Bulk density loose
The bulk density loose shall be determined in accordance with EN 12902.
7.2.3 Bulk density packed
The bulk density packed shall be determined in accordance with EN 12902.
7.2.4 Main product – barium sulfate Principle
Melting of mineral with sodium carbonate followed by disintegration in water and filtration to recover water insoluble carbonates. The solid is treated with hydrochloric acid solution and the acid insoluble fraction is filtered off.
Barium sulfate is precipitated by addition of ammonium sulfate solution and gravimetrically determined. Reagents
All reagents shall be of recognised analytical grade and the water used shall conform to grade 3 in accordance with EN ISO 3696. Ammonium hydroxide solution, NH 4 OH ρ = 0,9 g/ml. Ammonium sulfate solution, (NH 4 ) 2 SO 4 100 g/l solution. Hydrochloric acid, HCl ρ = 1,18 g/ml. Sodium carbonate, Na 2 CO 3 . Sodium carbonate solution, (Na 2 CO 3 ) 30 g/l solution. Methyl red, 0,5 g/l solution. Apparatus
Ordinary laboratory apparatus and glassware together with the following. Platinum crucible. Electric furnace, capable of being controlled at (850 ± 25) °C. Porcelain crucible. Oven, capable of being controlled at (105 ± 2) °C. Procedure
Weigh in the platinum crucible (, to the nearest 0,1 mg, about 0,5 g of barite previously finely powdered and dried at 105 °C (m 1 ). Add about 3 g of sodium carbonate (, mix and heat until the melt is clear. Cool and carefully disintegrate the solid with hot water. Filter and wash thoroughly the crucible and solid with hot sodium carbonate solution (
Transfer the filter paper and the filtered solid to a 250 ml beaker and acidify with hydrochloric acid (
Wash the crucible with few millilitres of hydrochloric acid and add the liquid to the solution. Boil the solution for 5 min and filter into a 600 ml beaker. Carefully wash the filter and the 250 ml beaker with water.
Add to the filtrate a few drops of methyl red indicator solution ( and ammonium hydroxide solution ( until the colour turns to yellow. Acidify the solution with 3 ml of hydrochloric acid ( and dilute to approximately 300 ml.
Heat the solution to boiling and add slowly 50 ml of ammonium sulfate solution ( stirring with a glass rod. Cover the beaker with a watch glass and allow to stand for at least 4 h at a temperature of about 80 °C. Then filter on a close-texture ashless filter paper. Wash the precipitate with boiling water until the chlorides disappear from the filtrate (test with silver nitrate solution).
Ignite the porcelain crucible ( in the electric furnace at (850 ± 25) ° C ( for 1 h. Place the crucible in a desiccator, cool to room temperature and weigh to the nearest 0,1 mg and note the mass m 0 . Place the filter paper with the precipitate in the ignited and weighed porcelain crucible and dry in an oven. Ignite the paper in air, then ignite for 2 h in the furnace at (850 ± 25) °C. Allow to cool in a desiccator and weigh to the nearest 0,1 mg (m 2 ).