WtRBSm CHEMiCALS DiViSiON ATLAS POWDER COMPANY, WILMINGTON 99, DELAWARE ATLAS P O W D E R C O m P A r CANADA, LTD., BRANTFORD, CANADA
Preventing haze in solutions by treatment with activated carbon Trouble-producing impurities of marginal solubility can o f t e n b e r e m o v e d by a c t i v a t e d c a r b o n b e f o r e t h e y materialize. T u r b i d i t y is generally caused by an ingredient t h a t is a t t h e point of precipitation when t h e solution is prepared, a n d l a t e r falls out of solution due to change in temperature, addition of other ingredients or some other action t h a t lowers solubility below t h e critical point. Most fiocforniing ingredients are large molecules . . . which are readily adsorbed by activated carbon. Sugar, for example, frequently contains organic impurities t h a t can cause h a z e . I n carbonated beverages, this lack of clarity would often be d e t r i m e n t a l to t h e acceptability of t h e finished p r o d u c t . T h e floe precursors m a y drop out of solution during carbonation. T o m a k e a sugar of t h e quality required by t h e beverage t r a d e , m a n y refiners use the D a r c o process in their manufacturing p l a n t . Beer is a n o t h e r p r o d u c t subject to h a z e formation. Certain nearly inseluble proteins in the beer will p r e c i p i t a t e out during extended periods of cold storage. B y giving the beer a small dosage of carbon in the ''cellar*' stage, these haze-formers are removed from t h e product and chill s t o r a g e life is considerably i m p r o v e d . If you h a v e a haze problem in y o u r p r o d u c t , let us h a v e t h e details about it. W e c a n probably give you recommendations on how to tackle the job w i t h a c t i v a t e d carbon.
Darco
cuts loss of valuable
Any time you're using activated carbon for purifying a valuable product, make sure you check on filter retention. Every activated carbon retains mechanically some of the treated product in the filter cake. Darco, however, holds less than other types of carbon. For example, in purification of vegetable oils, for each 100 pounds of carbon in the filter cake you get 60 to 90 pounds more VOLUME
3 3, N O .
29
·
·
·
products
oil out of the filter when you use Darco. This difference adds appreciably to profit, for it greatly reduces an important source of product loss. Darco activated carbons have many other qualities that add up to better efficiency of your filtering operations. AVe'd like to give you the story . . . just outline your specific problem and we'll send applicable data.
· JULY
!8,
1955
Crystal yield increased by carbon treatment The yield of product recovered from solution by crystallization frequently suffers from the presence of i m p u r i t i e s . W h e n crystallization inhibitors are in the mother liquor, only part of the product is crystallized out. Colloids are typical of the kind of materials that reduce crystal yield. By treatment with activated carbon, these impurities are physically removed from solution. An example of this technique is in the refining of sugar. Carbon treatment, intended primarily to decolorize, also takes out melassagenic impurities that impede crystallization. The result is an improvement in yield of crystalline sugar at the vacuum pans. This basic idea is a good one to follow: when recovering a crystalline product from solution, make the mother liquor a s pure as possible before crystallization, especially if you recycle the mother liquor... and you will obtain maximum crystal yield. Darco activated carbon is an excellent purifying agent for such applications. Write to us about your own recovery process, and we'll be glad to lend a hand. We're specialists in the use of carbon, and we can probably help you. 5
