Brine solutions

Uranium ores are leached with dilute sulfuric acid or an alkaline carbonate [3812-32-6] solution. Hexavalent uranium forms anionic complexes, such as uranyl sulfate [56959-61-6], U02(S0 3, which are more selectively adsorbed by strong base anion exchangers than are other anions in the leach Hquors. Sulfate complexes are eluted with an acidified NaCl or ammonium nitrate [6484-52-2], NH NO, solution. Carbonate complexes are eluted with a neutral brine solution. Uranium is precipitated from the eluent and shipped to other locations for enrichment. Columnar recovery systems were popular in South Africa and Canada. Continuous resin-in-pulp (RIP) systems gained popularity in the United States since they eliminated a difficult and cosdy ore particle/leach hquor separation step. 

Immersion curing is used as an alternative to dry curing. Immersion curing is stiU commercially used by some small processors. The meat is placed in a brine solution for an appropriate period of time until the brine penetrates the entire portion of meat. It is important not to keep the brine for too long a period of time because the brine strength is thereby reduced and the brine becomes contaminated with meat juices and bacteria. 

Electrochemical Process. Applying an electrical current to a brine solution containing propylene results in oxidation of propylene to propylene oxide. The chemistry is essentially the same as for the halohydrin process. AH of the chemistry takes place in one reactor. Most of the reported work uses sodium or potassium bromide as the electrolyte. Bromine, generated from bromide ions at the anode, reacts with propylene and water to form propylene bromohydrin. Hydroxide generated at the cathode then reacts with the bromohydrin to yield propylene oxide (217—219). The net reaction involves transfer of two electrons ... 

Water is softened by removing calcium and magnesium ions from hard water in exchange for sodium ions at sites on cation-exchange resin. Water softeners typically use a gel polystyrene sulfonate cation-exchange resin regenerated with a 10% salt brine solution (25). 

The costs of building and maintaining a bromine plant are high because of the corrosiveness of brine solutions which contain chlorine and bromine and require special materials of constmction. The principal operating expenses are for pumping, steam, environmental costs, energy, and chlorine. The plants are very capital intensive. 

In the recovery of cadmium from fumes evolved in the Imperial Smelting process for the treatment of lead—zinc concentrates, cadmium is separated from arsenic using a cation-exchange resin such as Zeocarb 225 or Ambedite 120 (14,15). Cadmium is absorbed on the resin and eluted with a brine solution. The cadmium may then be recovered direcdy by galvanic precipitation. 

Monovalent cations are compatible with CMC and have Httle effect on solution properties when added in moderate amounts. An exception is sUver ion, which precipitates CMC. Divalent cations show borderline behavior and trivalent cations form insoluble salts or gels. The effects vary with the specific cation and counterion, pH, DS, and manner in which the CMC and salt are brought into contact. High DS (0.9—1.2) CMCs are more tolerant of monovalent salts than lower DS types, and CMC in solution tolerates higher quantities of added salt than dry CMC added to a brine solution. 

Impurities remain in the brine solution and the sodium bicarbonate crystallizes and is filtered from the hquor. The bicarbonate is then converted to carbonate by heating ... 

Almost 40 years later the Lummus Co. patented an integrated process involving the addition of chlorine along with the sodium chloride and sodium hydroxide from the cathode side of an electrolytic cell to a tertiary alcohol such as tertiary butanol to produce the tertiary alkyl hypochlorite. The hypochlorite phase separates, and the aqueous brine solution is returned to the electrolytic cells. The alkyl hypochlorite reacts with an olefin in the presence of water to produce a chlorohydrin and the tertiary alcohol, which is returned to the chlorinator. With propylene, a selectivity to the chlorohydrin of better than 96% is reported (52). A series of other patents covering this technology appeared during the 1980s (53—56). 

In practice, the taffy process is generally employed for only medium molecular-weight resins (1) (n = 1-4). The polymerization reaction results in a highly viscous product (emulsion of water and resin) and the condensation reaction becomes dependent on agitation. At the completion of the reaction, the heterogeneous mixture consists of an alkaline brine solution and a water—resin emulsion and recovery of the product is accompHshed by separation of phases, washing of the taffy resin with water, and removal of water under vacuum. 

Salt Brines The typical curve of freezing point is shown in Fig. II-IIO. Brine of concentration x (water concentration is I-x) will not solidify at 0°C (freezing temperature for water, point A). When the temperature drops to B, the first ciystal of ice is formed. As the temperature decreases to C, ice ciystals continue to form and their mixture with the brine solution forms the slush. At the point C there will be part ice in the mixture /(/i+L), and liquid (brine) /i/(/i-t-L). At point D there is mixture of mi parts eutectic brine solution Di [concentration mi/(mi-t-mg)], and mo parts of ice [concentration mol m -t- mo)]. Coohng the mixture below D solidifies the entire solution at the eutectic temperature. Eutectic temperature is the lowest temperature that can be reached with no solidification. 

Brine Injection - After backwashing, a 5 percent to 10 percent brine solution is injected during a 30-minute period. The maximum exchange capacity of the resin is restored with 10 percent strength of brine solution. The brine is injected through a separate distributor placed slightly above the resin bed. 

Regenerant The solution used to restore the activity of an ion exchanger. Acids are employed to restore a cation exchanger to its hydrogen form brine solutions may be used to convert the cation exchanger to the sodium form. The anion exchanger may be rejuvenated by treatment with an alkaline solution. 

Clear Brines. Brine solutions are made from formation saltwater, seawater, or bay water, as well as from prepared saltwater. They do not contain viscosifers or weighting materials. Formation water-base fluids should be treated for emulsion formation and for wettability problems. They should be checked on location to ensure that they do not form a stable emulsion with the reservoir... 

Material requirements for brine solutions are given in Tables 4-63 through 4-65. 

Table 3.53 Corrosion of Type I Ni-Resist and cast iron in brine solutions...

Ice lollies are made from juice (water, sugar, citric acid, flavour and colour) and are frozen into shape using moulds immersed in a cold brine solution, in a similar manner to can ice making (see Section 12.4). The moulds are made from stainless steel or nickel, and pass in rows through a brine bath at - 45°C. Different layers of confection may be built up by allowing one outside layer to freeze, sucking out the unfrozen centre and refilling with another mix. The sticks are inserted before the centre freezes solid. The moulds finally pass... 

If a cucumber is placed in a concentrated brine solution, it shrinks and assumes the wrinkled skin of a pickle. The skin of the cucumber acts as a semipermeable membrane. The water solution inside the cucumber is more dilute than the solution surrounding it. As a result, water flows out of the cucumber into the brine (Figure 10.11, p. 273). 

When a cucumber is pickled water moves out of the cucumber by osmosis into the concentrated brine solution. A prune placed in pure water swells as water moves into the prune, again by osmosis. 

CONCENTRATION OF COPPER(II) IONS FROM A BRINE SOLUTION USING A CHELATING ION EXCHANGE RESIN... 

Theory. Conventional anion and cation exchange resins appear to be of limited use for concentrating trace metals from saline solutions such as sea water. The introduction of chelating resins, particularly those based on iminodiacetic acid, makes it possible to concentrate trace metals from brine solutions and separate them from the major components of the solution. Thus the elements cadmium, copper, cobalt, nickel and zinc are selectively retained by the resin Chelex-100 and can be recovered subsequently for determination by atomic absorption spectrophotometry.45 To enhance the sensitivity of the AAS procedure the eluate is evaporated to dryness and the residue dissolved in 90 per cent aqueous acetone. The use of the chelating resin offers the advantage over concentration by solvent extraction that, in principle, there is no limit to the volume of sample which can be used. 

In the illustrative experiment described here, copper(II) ions in a brine solution are concentrated from 0.1 to about 3.3 ppm prior to determination by atomic absorption spectrophotometry. 

Texture In the figure 2 the values of firmness along the process for two consecutive seasons is shown, very similar results were found for both seasons. The most important decreases took place during the lye treatment and subsequent wash step, reaching values of 50% of the initial. When the fruits were placed in the brine solution the firmnes recovered to 80% of the initial and, finally, during fermentation there was a new decrease to 60% of the initial. 

---