Barium chloride, recovery

On an industrial scale, only the reduction of europium(II) with zinc, followed by its recovery as a divalent sulfate from chloride solution is useful. In practive, it is possible to recover europium from mixtures containing only trace quantities by adding zinc, barium chloride and sulfuric acid the mixed... 

The alkaline process is less common than the acid process and provides lower recovery rates of uranium. For both processes, the ore must be first reduced to a size smaller than 75 p.m (mesh 200). Important radioactive pollutants from either process are Ra (radium 226) and Rn (radon 222). By adding barium chloride in settling ponds or lagoons, radium is treated. Radium-containing slurries and sludges are the subject of extensive research. Radium 226 decays to form radon gas from the tailings and is dangerous to health. 

Chemically related to barium, radium is recovered from its ores by addition of barium salt, followed by treatment as fur recovery of barium, usually as the sulfate. The sulfates of barium and of radium are insoluble in most chemicals, so they arc transformed into carbonate or sulfide, both of which are readily soluble in HC1. Separation from barium is accomplished by fractional crystallization of the chlorides (or bromides, or hydroxides). Dry, concentrated radium salts are preserved in sealed glass tubes, which are periodically opened by experienced workers to relieve the pressure, The glass tubes are kept m lead shields,... 

The raw minerals mined from natural deposits comprise mixtures of different specific minerals. An early step in mineral processing is to use crushing and grinding to free these various minerals from each other. In addition, these same processes may be used to reduce the mineral particle sizes to make them suitable for a subsequent separation process. Non-ferrous metals such as copper, lead, zinc, nickel, cobalt, molybdenum, mercury, and antimony are typically produced from mineral ores containing these metals as sulfides (and sometimes as oxides, carbonates, or sulfates) [91,619,620], The respective metal sulfides are usually separated from the raw ores by flotation. Flotation processes are also used to concentrate non-metallic minerals used in other industries, such as calcium fluoride, barium sulfate, sodium and potassium chlorides, sulfur, coal, phosphates, alumina, silicates, and clays [91,619,621], Other examples are listed in Table 10.2, including the recovery of ink in paper recycling (which is discussed in Section 12.5.2), the recovery of bitumen from oil sands (which is discussed further in Section 11.3.2), and the removal of particulates and bacteria in water and wastewater treatment (which is discussed further in Section 9.4). 

The precipitated barium 2-sulfonate always retains a certain quantity of the 3-sulfonate, which must be extracted with hot water. The precipitate is digested at the boiling point with 6-1. portions of boiling water until the residual salt is found to be free from isomers. The purity is determined from the melting point of the />-toluidine salt, in the manner described below. Usually two or three such washings are required. The mother liquor (B) from the barium 2-sulfonate is combined with the various washings, and the whole is boiled down to a volimie of about 6 1. Sulfuric acid (25-30 cc. of concentrated acid, diluted with water) is then added to precipitate the barium the filtered solution (Note 6) is concentrated to about 2 1. and neutralized with potassium hydroxide to bring down a mixtime of potassium sulfonates (C). The filtrate from the potassium salts may be boiled down further and treated with potassiiun chloride to insme complete recovery of the potassium sulfonates, and then discarded. The potassium salt mixture collected in these operations is set aside (C). 

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