The basic guidelines of Technical grade borax powder are well known, and the worst case I have seen is guaranteed to have less than 700 ppm of chloride. Under what circumstances could that amount of chloride NOT be dissolved in the first solution? I am depending on the total chloride, sulphate and iron which total 1330 ppm max in the original charge of borax to be dissolved in the first charge of water, 95% of which will be removed by decanting it. That solution certainly would yield a more contaminated borate powder than the original if it were evaporated. I would in fact be happy if it had only the soluble impurities and no borax. Instead, it will be discarded or used for drain cleaner or one of several other household uses. How can what remains in the undissolved borax not have less chloride than it had before? What if it does have more insoluble impurity? I am not using the insoluble impurity that remains. I am making a second saturated solution from it, leaving insoluble impurities behind. The second saturated solution removes doubt about hydration of the powder and MUST have smaller percentages of chloride, sulphate and iron. Why, in the name of good science, don't you read thoroughly what I wrote?
Originally Posted by Photo Engineer