Dyes and Pigments
Dye desalting and concentration
The final product liquor obtained in the manufacturing process of reactive and acid dyes, residues of salt and low molecular weight complexes are present which causes interference in the dyeing strength and finish. SepraTECH provides an excellent solution of not only desalting the dye but also concentrate them with the help of membranes, thus increasing the quality of the final dye product. Use of Nano-Filtration membranes helps in stabilising the product and also avoids the precipitation of salt in the holding vessels. SepraTECH has immense experience and technology in the dye industry by conducting many pilot plant trials and has solved many complex water challenges.
Compared to conventional methods of chemical and biological treatment, SepraTECH has mastered technology and innovation in removal of colour from streams. With the help of advanced membrane technology, SepraTECH can cater to industries in removing of colour in the most economical manner. As of today, it is a requirement of every industry to minimise environmental release of colour, even in cases where a small but visible release might be considered as toxic.
Unlike dyes, which either is itself a liquid or is soluble in its vehicle (resulting in a solution), pigments are insoluble in its vehicle(resulting in a suspension). Pigments are insoluble non-ionic compounds or insoluble salts and retain their crystalline or particulate structure throughout their application.
Removal of pigments from streams requires lot of chemicals which ultimately leads to large amount of sludge. Wash water from pigment process vessels mainly constitute of water, impurities,salts and pigments in undissolved form which if passed through ETP has to undergo a long process with end result being creating a lot of sludge after settling. SepraTECH has a process technology which can take care of the suspended nature of the pigments with the help of larger channel diameter membranes.
Impurities such as glauber’s(Na2SO4) and other lower molecular salt impurities can be removed with the help of nano-filtration membrane processes. Membrane processes help in concentrating the dye liquor hence decreasing the operational costs of a spray dryer by lowering the energy levels significantly achieved by concentrating the feed through membrane solutions. By having a membrane system we can remove the impurities to a tune of more than 95% purity and minimum dye loss(0.1%). Our systems can concentrate dyes from initial concentration of 5-10% to 15-30% depending on the solubility of the dye.