Bleach liquor

Bleach liquor Bleach, supertropical Bleach systems Blended asphalt Blended whiskey Blenders Blending Blends... 

Bleach Liquor. Bleach Hquor or lime bleach Hquor is an aqueous solution of calcium hypochlorite and calcium chloride. It typically contains 30—35 g/L of available chlorine, though it may be as high as 85 g/L. It has been used in pulp bleaching, when it can be made more cheaply than sodium hypochlorite. It is prepared on site by chlorinating lime solutions. 

Calcium Hypochlorite (Bleach Liquor). Bleach hquor is a solution of Ca(OCl)2 and CaCl2 containing some dissolvedhme. The av CI2... 

About 93% of the CaCOs mud is dried and lecalcined in rotary kilns to recover the CaO. Calcium hypochlorite bleaching liquor (p. 860) for paper pulp is obtained by reacting lime and CI2. 

Bleaching powder patented by C. Tennant (CI2 4- slaked lime) following preparation of bleaching liquors from CI2 and lime solutions by T. Henry (1788)... 

Bleich-anlage, /. bleaching establishment, bleaching plant, bleachery. -anstalt, /. bleachery. -artikel, m. (Calico) bleach style, -bad, n. bleaching liquor or bath. 

Menger (1993) has brought out an unusual application of ME, through what is called chemical collectivism for destruction of toxic mustard CI-CH2-CH2-S-CH2-CH2-CI with bleach liquor. 

Despite its technical usefulness, hypochlorite bleaching faces severe environmental pressures because it yields A OX values well in excess of permitted levels. The A OX value observed increases with the active chlorine content of the bleach liquor (Figure 10.31) and with the time of treatment (Figure 10.32). 

When bleaching wood pulp in a paper mill, the amount of leftover or residual hydrogen peroxide present in the spent bleach liquor can be important. Sometimes the bleach liquor is used in a second bleach or recycled back to the first bleach. Also, the residual peroxide level can indicate whether the bleach liquor makeup needs adjusting. Laboratory scale bleach tests are performed on the wood pulp, and the residual peroxide levels are checked by titration of the spent bleach liquors using potassium iodide and sodium thiosulfate. By monitoring the residual peroxide levels of these bleaches, the bleach liquor makeup can be adjusted, giving the best level, as needed by each paper mill. 

As early as 1788, Thomas Henry prepared a bleaching liquor from lime and chlorine, and it became a common practice among bleachers to economize by substituting lime for the more expensive pearlash from wood ashes (123). In 1795 the Hungarian botanist and chemist Paul Kitaibel distilled a mixture of salt, pyrolusite, and sulfuric acid, and passed the liberated chlorine ( oxygenated acid of salt ) into limewater. He made many experiments with solid bleaching powder, and used it to bleach textiles and wax (125). 

G. Blattner studied the action of metallic oxides on the alkali hypochlorites and on bleach liquor during 15-20 days. The oxides of cobalt, nickel, and coppet... 

In addition to soln. of chloride of lime—lime bleach liquor—bleaching liquids with magnesium, zinc, or aluminium hypochlorites as the active agents have also been made and special virtues claimed for their use. For example, if magnesium sulphate be added to a soln. of bleaching powder, calcium sulphate is precipitated and a soln.—magnesia bleach liquor—of magnesium hypochlorite can be decanted off similarly with zinc hypochlorite—zinc bleach liquor and with aluminium hypochlorite—alumina bleach liquor, or Wilson s bleach liquor. 

In 1851, C. Watts1 patented a process for preparing chlorine, soda, hypochlorites, and chlorates by the electrolysis of soln. of alkali chlorides but little progress was made for many years. In 1882, A. P. Lidoff and W. TichomirofE described the preparation of hypochlorites by this process, and in 1883, E. Hermite patented a process, for the preparation of electrolytic bleaching liquor, which has been used in several countries, but is now regarded as an obsolete process. 

Numerous other types of cell have been devised, and several of these have a much greater efficiency than the Hermite cell—e.g. K. Kellner s,2 Schuckert and Co. s, ML Haas and E. Oettel s, and P. Schoop s systems. The electrolytic production of chlorine and caustic soda, of bleaching liquors, and of disinfecting liquid—e.g. the so-called Dakin s solution—are growing industries. 

---