TOTAL HARDNESS (Calcium & Magnesium)

Water containing large amounts of Calcium or Magnesium Salts is commonly referred to as “hard water”. Make up waters that are hard make it difficult to obtain the maximum yield from Bentonite, so it becomes necessary to treat out excess Calcium.
As a general rule, the total hardness as Calcium should be brought to less tan 40 mg/L.
The presence of Calcium in the mud filtrate may also indicate the presence of contaminants, such as anhydrite or cement.


Test Procedures Total Hardness (as Calcium)::
•Using a pipette, measure 1.0 ml of filtrate into a white titration dish, and dilute to a convenient volume with distilled water.
•Add 4-5 drops of strong Buffer solution, and 2-3 drops of Indicator. A red or wine color will develop if Calcium is present.
•While swirling or stirring continuously, add Total hardness titrating solution with a pipette until the color changes from red to blue. At this end point, record the number of milliliters of Total hardness titrating solution added. Calculations: Total Hardness (as Calcium): mg/L Hardness (as Calcium) = 400 X ml Total hardness titrating solution added Calcium Hardness:
•Using a pipette, measure 1.0 ml of filtrate into a white titration dish, and dilute with a small amount of distilled water.

•Add 2-3 drops of 8N KOH (Potassium Hydroxide) solution.
•Add several grains of CalverII, and swirl or stir to mix.
•Using a pipette.
Titrate with Total hardness titrating solution solutionto a color change from red to blue
Calculations: mg/L Calcium Ion = 400 X ml Total hardness titrating solution added Magnesium Hardness: –The Magnesium hardness is calculated as follows: mg/L Magnesium = mg/L Total Hardness (as Calcium) –mg/L Calcium