Recycling is an important activity in the minimization of waste that results from human activities. In the United States, 103.2 billion pounds of plastic are produced in 2011. Unfortunately, the majority of this plastic ends up in landfills where its decomposition process can take anywhere from 10 to 30 years. In this work, froth flotation was used to treat PVC (polyvinyl chloride) and PET (polyethylene terephthalate) mixtures. The parameters studied are fed mixtures component ratios, concentration of Calcium Lignosulfonate as wetting reagent and a number of cleaning flotation. The results show a yield of 100% pure PVC separated from PET.

Large reserves of feldspar ores exist in the pegmatite veins at Ban Tak district, Tak province. The main impurities of these deposits are muscovite, biotite and garnet which resulted in high Fe-content that does not meet the raw materials specification for ceramic industry. Chemical compositions of the feldspar ores are 75.93 %SiO2, 14.34%Al2O3, 0.63% Fe2O3, 4.01%K2O and 4.34%Na2O with the fire test results of L= 63.10, a = 2.04 and b = 10.56. The typical specifications of the commercialised feldspar require %SiO2, <70%, Al2O3 >17%, Fe2O3 <0.1% with K2O and Na2O both >5%. The traditional method used to remove Fe-bearing minerals is the reverse flotation. However, this method consumes high sulphuric acid which may create the environmental impact for the nearby area if the treatment is not completely done or the accident occurs. The proposed processes combine the typical process of crushing, grinding and classifying, attrition scrubber, with the wet high intensity magnetic separator (WHIMS) and the direct flotation of feldspar. WHIMS is used to remove muscovite, biotite and garnet which are the causes of high Fe-content. The results showed that efficient separation of Fe-bearing minerals could be achieved by WHIMS in the commercial scale and create the environmental friendly manner. The recovery of processed feldspar is 40% and the chemical compositions of feldspar products are 68.29 %SiO2, 18.69% Al2O3, 0.07% Fe2O3, 5.83% K2O and 6.33%Na2O with the fire test results of L= 82.10, a = -0.56 and b = 3.23 which meet the commercial grade of feldspar.

Abstract. The purpose of this research is to recover slime waste from feldspar flotation plant at Attanee International Co., Ltd., Tak province. Slime waste with particle size less than 230 mesh, is found about 20% of the total ore feed. Since 1985, company has been producing slime waste approximately 200,000 tons, causing a huge pile of stock and obstructing the operation area. The mineral compositions of slime waste by X-Ray Diffraction (XRD) showed that it consisted of albite, orthoclase, quartz, and ferrous impurity minerals such as muscovite, biotite, mica, and garnet. The elemental analysis by X-Ray Fluorescent (XRF) showed that the percentage of grade contained 72.53% SiO2, 15.70% Al2O3, 1.56% Fe2O3, 0.16% TiO2, 0.40% CaO, 0.07% MgO, 4.87% K2O and 4.38% Na2O. After that, this slime waste was sent to the processes of dirt washing, classifying, attrition scrubbing, separating the ferrous impurity minerals, and preparing for flotation by washing drum, trommel, attrition scrubber, cone classifier, permanent drum magnetic separator, wet high intensity magnetic separator, and hydrocyclone. At this stage, the slime mainly consisted of albite, orthoclase, and quartz with 74.43% SiO2, 15.15% Al2O3, 0.12% Fe2O3, 0.04% TiO2, 0.43% CaO, 0.01% MgO, 4.73% K2O and 4.75% Na2O at a yield 35%. Study on fine feldspar flotation, which is for removing quartz from feldspar, showed that the optimum condition of 20% solids must be adjusted to pH 2 by hydrofluoric acid (HF), using A-TD as a collector at 1,400 grams per ton feed, conditioning time and flotation time of 5 minutes each. The results of the study showed that the recovery of feldspar attained 69.7% with 67.82% SiO2, 18.54% Al2O3, 0.14% Fe2O3, 0.03% TiO2, 0.52% CaO, 0.006% MgO, 6.88% K2O and 6.07% Na2O, which meet ceramic industry's specifications.

Abstract. The beneficiation of cassiterite fines from tailing dumps in the Jarin Tin Mine, Thailand were studied through a wet concentration process and dry electrostatic and magnetic processes. The tailing dumps with the size of mineral smaller than 5 mm was collected through the tin mining in the area 20 years ago with the total amount of 17 million tons. The huge pile of the tailing dump may impact environmental in the area, so they need to be treated and recovered for the valuable heavy minerals and sand tailing for the local construction industry. The grade of the tailing dumps are 0.05% Sn, 0.002% Nb, 0.001% Ta. After the wet processing by the screen, hydrocyclone, spiral concentrator, and shaking table, the concentrate consist the most of cassiterite, ilmenite, garnet, zircon, monazite, xenotime, and quartz, containing 20% Sn with a yield of approximately 0.2%. The following dry processes used rotary dryer, screening, electrostatic separator, magnetic separator to separate cassiterite from the heavy minerals and quartz. The final tin concentrate can be upgraded to 72% Sn which can be sold to the tin smelting plant. The economic analysis of the cassiterite recovery processes was conducted using the discounted cash flow model in order to address the cost and benefit of the processes.

Microplastics (MPs), the plastic particles with size fraction smaller than 5 mm, are recently becoming one important problem worldwide due to their ubiquitous distribution in the environment, especially in water. In this study, the separation techniques in mineral processing (i.e., magnetic separation and surface-based separation) were applied to remove MPs from contaminated water. Five kinds of model MPs samples (+38−2000 μm); polypropylene (PP), polyethylene (PE), polystyrene (PS), polyethylene terephthalate (PET), and polyvinyl chloride (PVC) were used and magnetite (Fe3O4) powders (−75 μm) were modified using hexadecyltrimethoxysilane (HDTMS) to change their surface from hydrophilic to hydrophobic for MPs recovery. The results showed that MPs could be attached on the surface of modified magnetite due to the hydrophobic interaction and could be recovered together with modified magnetite by magnetic separation.