Calcium chloride brine

Mixing Chart for Heavy Brines Using Calcium Bromide and Calcium Chloride Brines and Calcium Chloride Pellets... 

For many years such media have been based on strong salt solutions, e.g. calcium chloride brines. Sodium dichromate has been used (seep. 17 26), but recently other inhibitors have been claimed to be effective. One patent quotes N-alkyl-substituted alkanolamines, e.g. 2-ethyl ethanolamine -I- BTA at pH A mixture of hydrazine hydrochloride -i- BTA has been claimed as well as a mixture of gelatin -h triethanolamine -h potassium dihydrogen phosphate . Other examples are to be found in the patent literature and the above are quoted to illustrate the diversity of chemicals that may be used. 

The general method is to drive in a ring of vertical pipes and pass chilled brine down through an inner pipe so that it flows up the annulus, to cool and eventually freeze the surrounding wet soil. This process is continued until the ice builds up a continuous wall around the proposed excavation. Depths of over 650 m have been excavated in this way. Calcium chloride brine, cooled by surface plant, is usual, but liquid nitrogen has been used on small shafts [50]. 

When chlorination has to be carried out at a low temperature, it is often beneficial to circulate cooling water through a lead coil within the chlori-nator or circulate the charge through an outside cooling system rather than to make use of an external jacket. When the temperature is to be maintained at 0°C or below, a calcium chloride brine, cooled by a refrigerating machine, is employed. 

The effluent from the magnesium hydroxide process is a 25 percent calcium chloride brine. The water in the brine is boiled away with steam in triple-effect vacuum evaporators to make 32-45 percent CaCl2. Alkali chlorides precipitate in the evaporators and... 

Donald F. Othmer while at Eastman Kodak during the 1920 s experimented using salts to concentrate acetic acid (14). He also developed an industrial process for distilling acetone from its azeotrope with methanol by passing a concentrated calcium chloride brine down the rectification column (15). Pure acetone was condensed overhead, and acetone-free methanol was recovered in a separate still from the brine which was then recycled. The improved Othmer recirculation still (16) has been the apparatus generally favored by investigators who have studied the effects of salts on vapor-liquid equilibrium. 

Sass E. and Starinsky A. (1979) Behaviour of strontium in subsurface calcium chloride brines southern Israel and Dead Sea rift valley. Geochim. Cosmochim. Acta 43, 885-895. 

Many authors have proposed that the rock environment, through a series of chemical reactions, will extensively modify fluids in contact with it (Chebotarev, 1955 Collins, 1975 Edmunds et al., 1984, 1987). Early research in this area suggested that long-term evolution of subsurface saline fluids favored the formation of calcium chloride brines that are very old. However, the origin of these brines could not be determined (Krotova, 1958 Rittenhouse, 1967). 

The earliest studies of Canadian Shield brines found that calcium chloride brines, with salinities up to 340 g were ubiquitous at more than 20 sites below depths of 1,000 m (Fritz and Frape, 1982). As these sites were active working mines, the rock mass was disturbed, so there was usually a component of freshwater circulating through the rock mass to depth. This water tended to mix with older brackish to brine solutions, but also seemed... 

Starinsky A. (1974) Relationship between calcium—chloride brines and sedimentary rocks in Israel. PhD Thesis, The Hebrew University, Jerusalem, 176pp. 

There has also been corrosion from the calcium chloride brine on the inside of the tubes in spite of pH control. Inhibitors are now being investigated. 

In other processes similar to the Solvay process (see Section 3.1.1.3.3), potassium carbonate is produced directly from potassium chloride with amines such as isopropylamine via a potassium hydrogen carbonate step, but contaminated calcium chloride brine is produced as a byproduct whose disposal poses environmental problems. In the former States of the USSR potassium carbonate is also produced from alkali aluminosilicate deposits (e.g. nepheline) together with aluminum oxide, cement and sodium carbonate. 

About 10% of the raw rock, comprising silica and the like, does not dissolve. However, this material is readily removed by settling the dilute slurry in a thickener, sometimes aided by coagulants (Fig. 6.6). The clarified solution from the thickeners is then extracted with a C4, C5 alcohol mixture or trialk-ylphosphate in a series of three or more mixer settlers producing a solvent phase rich in phosphoric acid, and a raffinate of calcium chloride brine freed of phosphate. Presence of the calcium chloride salt in the aqueous phase undoubtedly assists in driving the phosphoric acid transfer to the organic phase by making the aqueous phase more polar. 

Aqueous fluids are normally formulated with corrosion inhibitors. Because these fluids are ionic, improper selection of corrosion inhibitors can lead to severe corrosion. Glycols and brines are normally not recommended with galvanized steel and soft solder. Aluminum systems are not recommended above a certain temperature. Sodium and calcium chloride brines are very corrosive toward most of the metals even with the inhibitors. 

CALCIUM CHLORIDE - A substance used to obtain calcium chloride brine. 

Solvent Recovery From Spent Calcium Chloride Brine.347... 

Extraction - Extraction is performed by a counter-current contact of dissolution liquor vwth the selected solvent. Phoqihoric acid transfers selectively from the aqueous dissolution liquor to the organic solvent phase the resultant extract and calcium-chloride brine (raffinate) contain substantiaDy all the impurities, such as fluorine and iron. 

Stripping-The acid-free solvent stream extracts the residual acids present in the raffinate and is recycled to extraction. The spent calcium-chloride brine is stripped by steam to recover any dissolved solvent. 

As noted in (Box 1.5), the lowest temperature at which calcium chloride brine can be used is -52°C (-62°F). Assuming a -F6.rC (+1TF) heat exchange approach (temperature difference), the value of -45.9 C (-50.6°F) is the lowest temperature to which solvent vapor can be chilled (condensed). 

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