Pelletizing of Bark Residue Resulting from Debarking of Softwood Trees

Debarking is an essential part in the technology of round timber processing. The volume of bark going to waste annually is millions of cubic metres, therefore the use of bark as an underexploited renewable source is of increasing importance. Pelletization is one of the recognized methods for increasing the bulk and energy densities of plant biomass, and respectively improving its value as a fuel. Plant biomass pellets are the only solid fuel that have a global constantly growing market. In this work the bark obtained after softwood trees debarking for the pulp manufacture was studied in terms of fuel pellets production feasibility. The fuel characteristics, including elemental composition, ash content, calorific values and other parameters required for fuel pellets standards were determined. The laboratory flat die pellet mill KAHL 14-175 was applied for pelletizing study. The study showed that using floatation process for purification / fractionation of bark batch under study, 86% of bark residue become suitable for obtaining of fuel granules quality of which meet the demand of EN 14961-2B European standard for non-industrial and industrial fuel pellets.

Evolution of Floatation Equipment for Sewage Treatment аnd Active Sludge Thickening

The article covers theoretical basics of floatation process and main stages of flotators’ evolution. special attention is paid to flotation as multistage process as well as to definition of constants with theoretical and the experimental methods. Authors demonstrate that use of theoretical bases of multistage flotation model allows to significantly stimulating floatation process. Leading foreign and domestic innovations in floatation sewage treatment and active sludge thickening are presented. Promising research in constructing multi-tool floatation apparatus (flotation combine) is described. The article provides variants of multi-tool flotators’ design, examples of its integration into operation, and the test data confirming its high effectiveness for sewage treatment and active sludge thickening. Methods of stimulating thickening with carbon dioxide and chemical agents are used for wastewater sludge (including active sludge).

Process Mineralogy Study of a Refractory Mixed Copper Ore

Process mineralogy research of a mixed copper ore is studied to identify the occurrence mode of copper and to analyze the mineralogical factors influencing the floatation results. The results show that the ore has features of "high-sulfur, high copper", "various copper mineral types", "fine copper mineral granularity" "disorderly copper mineral distribution", which belongs to the more difficult processing high sulfur mixed copper ore. Therefore, in order to effectively utilize the copper mine resource, floatation process or combination of floatation-hydrometallurgy process should be adopt.

Comparison of Combination of Flotation-Magnetic-Gravity Separation Process with Bluk Flotation for Recovering Fine Tin Slime

A comparative analysis of the combination of flotation-magnetic -gravity separation with bulk-floatation process for recovering fine tin slime was carried out in a mineral processing plant. Compared to the bulk floatation process, the flotation-magnetic-gravity separation process resulted in a higher recovery of tin and showed advantages of small consumption of reagents and electric power, stable production index and easy operation.

An Instance about Juice Wastewater Treatment with UASB and Bio-Contact Oxidation and Coagulation and Floatation Process

UASB, bio-contact oxidation, coagulation and floating process was adopted in treatment of juice wastewater. Operation results show that when the main pollutants of COD, BOD and SS in the influent were 6033 mg•L-1, 2512 mg•L-1 and 2200mg•L-1, the effluent could reach 63 mg•L-1, 25 mg•L-1 and 29 mg•L-1, respectively, with the removal rate of 99.0 %, 99.0 %, 98.7 %. The effluent reached the I-class criteria specified in Integrated Wastewater Discharge Standard (GB8978-1996) (COD < 60 mg•L-1, BOD < 20 mg•L-1, SS < 20 mg•L-1). The process provides a practical reference for the similar high concentration organic wastewater treatment processing.

Fate and Transport of Pathogens of Reclaimed Water in Floatation System

Reclaimed water contains a mass of pathogenic microorgansims, one of the main concerns for reclaimed water reuse is the microbiological water quality and thereby the possibility of spreading diseases. In recent years, most researches focused on deep treatment of waste water. However, few studies have considered variation mechanism and transport of pathogenic microorgansims in different environment .With the more and more application of reclaimed water in mining field, we should pay more attention to hygienic safety. The inactivation by temperature, grinding, flotation reagents and adsorption of pathogens with mineral particulates are of particular importance in determining pathogens transport and distribution. Consequently, based on a synthetical pathogenic microorgansims index, study should center on the effect of floatation environment and floatation process on survive of pathogenic microorgansims and variations mechanism; the fate, temporal and spatial distribution of pathogenic microorgansims in floatation system; transport disciplinarian of pathogen in floatation process. The result of this study provides a basis and technical advice for reclaimed water safety renovation and wastewater treatment technology.

Treatment of Oily Sludge from Floatation Process: Floc Breakage and Dewatering

The aim is to treat oily sludge from floatation process of oil produced water by deflocculation. Based upon analyzing the granularity distribution and dewater efficiency of the flocs, floc breakage and dewater of oily sludge was carried out. The results indicated that the coagulant skeleton builder in sludge could be broken by changing the coalescent state, and deflocculation could disrupt skeleton of the floc and release interstitial water in sludge. The highest dewatering efficiency is about 81.2% at the pH of 4.5 by gravity sedimentation. The sludge had a broader range of granularity distribution and a smaller volume-average diameter. Moreover, the median diameter d (0.5) of the treated sludge was 36.0 μm, which was smaller than 73.1 μm of raw sample. Meanwhile, capillary suction time (CST) significantly decreased with pH adjustment. A wastewater removal efficiency of 90.99% for the treated sludge by pressure filtration could be achieved. The method would be a potential technique to be applied to other kinds of floatation sludge.