Example 1
100 kgs. of "garnet" conglomerate of Lonedo (Vicenza) containing about 2.5% of ZrO2 are finely pulverized and introduced into a rotary cylinder lined with siliceous material and submitted to a slight beating with 5.2 kgs. of precipitated magnesium fluoride such as Is freshly extracted in a subsequent phase of the operation which will be described hereinafter, and with 50 kgs. of a salt-acid solution of potassium chloride and of HC1 having a content of 15< to 16% of potassium chloride and 8% of hydrochloric acid respectively. This pasty mixture is left for reaction during some hours while promoting the reaction by a fresh slow mixing and a moderate heating up to 65-65° C., after which the mixture is introduced into a very powerful press which expels all the liquid from it, and then the residue of this operation is lixiviated with small quantities of water and the briquettes which are thus obtained are introduced into a burning furnace. The expelled liquid, which is composed of a solution of magnesium chloride and of potassium chloride is collected in a large vessel. In the burning furnace the briquettes are heated up to a temperature of about 600° C. during a time which varies between 1 hour and 1 hour and a half or two hours, and after cooling and crushing the product is washed and then the filtered liquid is collected, while the residual mineral gangue Is washed and released from the salts which it still contains in a liquid suspension, and then discarded.
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