The Purification Of Calcium Carbonate In The Sugar Mill Filter Mud And Its Application In Papermaking

Sugar industry produce the sugar while it also can produce a large number ofby-products and waste. The sugar mill filter mud is a large amount of waste, it has a largequantities and pile up like mountains. It contains some organic matter and it can go mouldyand stink easily, so it is easy to cause environmental pollution, but the calcium carbonatecontent can reach more than80%in the dry filter mud by carbonate method, calciumcarbonate is important chemical products, and it is often used in papermaking, rubber,plastic, etc. So if the mud filter be reasonable use, it not only can reduce the pollution of theenvironment and will greatly reduce the products cost and make the filter mud into a goodthing.So, the sugar mill filter mud is used as the experimental object to discuss the resourceutilization of filter mud in this paper. We study the composition determination of sugar millfilter mud, the screening and identification of the purification bacteria in the sugar mill filtermud, the optimization of the method of purifying the sugar mill filter mud with thepurification of bacteria, the application of the sugar mill filter mud in papermaking andseveral other aspects.The total nitrogen content in filter mud is determined by kjeldahl determination andcoomassie brilliant blue method, using phenol sulfuric acid method measure the content of thetotal sugar in the filter mud, the content of metal elements was measured by atomic absorptionmethod in the filter mud, with ammonium molybdate method measure the content ofphosphorus in the filter mud. The experimental data show that the crude protein content is2.3%, total sugar content is6.4%, the total phosphorus content is1.52%, potassium content is0.031%, the content of calcium is35.79%, the content of sodium is0.032%, the content ofmagnesium is0.72%, the content of iron is0.205%in the sugar mill filter mud.The experiment screened two kinds of mold what were mold of fv1and mold of fv2,which can be efficiently purify filter mud from sugar mill filter mud by the first screening andthe rescreening. The two kinds of mold were identified as Rhizomucor and Aspergillus bymorphological identification and molecular biological identification. The test selected that the temperature, pH and inoculum size were selected as theindependent variable with the sugar consumption as response values. Besides, using responsesurface methodology optimized the conditions of mould purifying the sugar mill filter mud.Using the method of analysis of variance and Box-Behnken design, we studied the influencesof the variables and their respective interaction affects on sugar consumption and then,attained the model of the regression equation. The results showed that the optimum conditionsof temperature, pH and inoculum size were30℃,8and16%, respectively. With thisunderstanding, the actual sugar consumption was1040mg/20g and the relative error was1.97%compared with the theoretical value of1061.39mg/20g.The paper selected the best bleaching agent which used to bleach the sugar mill filtermud, and then confirmed the best condition of the best decolorizer through experiments.Finally the effects of different dosage of filter mud on the paper performance were discussed,and compared with the paper performances using the product of light calcium carbonate (pcc)under the same conditions. The experiment showed that the best decolorizer was PL2and theoptimum temperature, additive amount and time were100℃,6%and1.5h, respectively. Withthis understanding, the brightness of filter mud can reach60%ISO. The optimal dosage offilter mud was confirmed to20%with the papermaking adding test. And comparing with thepapers added with pcc, a number of paper properties added with filter mud was improved onthe same conditions.