Papers by Abel Bissombolo
REWAS'04 - Global Symposium on Recycling, Waste Treatment and Clean Technology, 2005
RESOURCES PROCESSING, 2000
RESOURCES PROCESSING, 1999
RESOURCES PROCESSING, 1999
RESOURCES PROCESSING, 1996
RESOURCES PROCESSING, 2003
RESOURCES PROCESSING, 1996
RESOURCES PROCESSING, 1997
Developments in Mineral Processing, 2000
Abstract In order to obtain economically lot of fine particles, a dry tower mill KD-3, composed o... more Abstract In order to obtain economically lot of fine particles, a dry tower mill KD-3, composed of a comminuting section, a classifying column and a collecting section, has been developed through this study. Grinding tests were carried out on limestone to clarify the comminution mechanism in the KD-3. A particular attention was paid to important factors such as the size of the grinding media (steel balls of10 mm,13 mm,16 mm,20 mm), the speed of the stirring screw (from 1.08 s −1 to 1.58 s −1 ) and the role of the net in the classifying column. The study has revealed an optimum efficiency for steel balls of20 mm size and a stirring screw rotating at 1.58 s −1 . Besides, a series of nets settled in the classifying column have improved the efficiency of the classifying operation by reducing the buoyancy of the materials and regulating the maximum size of products collected in the cyclone (d max is about 10 μm). The air flow rate in the duct and the pressure of drops in the column were approximately quadratic curves, but the d max of products collected in the cyclone was proportional to the pressure of drops in the classifying column.
RESOURCES PROCESSING, 1995
Investigations were carried out on feed and products (concentrate, middling, tailing) from the "K... more Investigations were carried out on feed and products (concentrate, middling, tailing) from the "Kyoei Chemical Industries" processing plant to establish, at various size range, the degree of liberation of fluorite from the other gangue minerals (quartz, feldspars,...) and determine the size range at which serious losses are occurring. The results of a careful microscopic counting of free minerals and various kind of mineral associations present in each fraction interpreted on the basis of the Gaudin's liberation model have been used to assess the efficiency of the beneficiation. It is suggested to reduce the cut off grain size in the classified ore from 0.5 mm to 0.3 mm in order to increase the selectivity of the flotation process.
RESOURCES PROCESSING, 1999
Resources Processing, 2006
Automobile Shredder Residue (ASR) is composed of many kinds of combustible substances but contain... more Automobile Shredder Residue (ASR) is composed of many kinds of combustible substances but contains a few quantities of copper, which is considered to be a catalyst of dioxins when it is incinerated with chlorine. In this study, a dry tower mill and an electrostatic separator were used to carry out the experiments on the reducing of copper from the agglomerated light ASR materials. It was found that the products after agglomerating the light ASR materials (RDF) could be easily comminuted with 20 kg of steel balls for 20 minutes and the weight percentage of the fraction of −1 mm reached 66.0% at 200 r.p.m while it was very hard to comminute the light ASR materials themselves. Moreover the content of copper in the comminuted product could be reduced from 2.25% to 0.17% by electrostatic separation although the content of other metals such as zinc, lead and aluminum could not be reduced.
Separation and Purification Technology, 2005
Experiments were carried out with waste phosphors collected during the recycling of end-of-life f... more Experiments were carried out with waste phosphors collected during the recycling of end-of-life fluorescent lamps to obtain a highly enriched phosphors product as starting material for the better extraction of rare earth elements. The aim of this work was therefore to separate low-density calcium halo-phosphate phosphors from high-density rare earth-activated phosphors through dense-medium centrifugation (with di-iodomethane as organic dense-medium). The
International Journal of Mineral Processing, 2002
In the theory of grinding kinetics, the grindability of a material is the only factor used to det... more In the theory of grinding kinetics, the grindability of a material is the only factor used to determine the required size of a grinding machine. So for users of the Tower mill, this grindability is expressed through Bond's work index (W i). However, the uniformity constant (n), which is found empirically by using a small Tower mill and is expressed also as the grindability of material, can be of great help to designers in the determination of the real parameters of a Tower mill. The present study is an approach to establish a relationship between the Bond's third theory of comminution and the above-mentioned constant of grinding kinetics. The validity of the obtained relationship, ½n ¼ 1:47 À 0:309ln½W i ; has been confirmed with a correlation coefficient of 0.855** through a regression analysis of 22 samples of limestone.
International Journal of Mineral Processing, 2005
Zeta-potential measurements were made to determine the electric state of phosphor materials on th... more Zeta-potential measurements were made to determine the electric state of phosphor materials on the basis of which a feasibility study could be performed for the use of flotation in the recovery of fine (d 50 b 13 Am) rare earth phosphors from waste fluorescent lamps. Tests were carried out with pure specimens of white (calcium halo-phosphate), red, green and blue (rare earth) phosphors, with a 17 : 1 : 1 : 1 ratio of their mixture, and with actual waste phosphor materials. The effects of a cationic (dodecyl ammonium acetate, DAA) and two anionic (sodium dodecyl sulfate (SDS) and sodium oleate (NaOl)) collectors on the floatability of materials, as well as that of Na 2 SiO 3 dispersant on the separation characteristics, were investigated at different pH ranges. The process, applied to actual discarded waste phosphors gave, in a two-stage separation scheme, sink products assaying 17.7-23.8% and 21.5-25.9% rare earth phosphors for DAA and SDS flotation, respectively. The recovery and Newton's efficiency were about 70-90% and 0.26-0.37, 66-82% and 0.18-0.20, respectively for DAA and SDS flotation.
RESOURCES PROCESSING, 1995
Experiments were conducted on fluorite to identify all the mineral components and elements distri... more Experiments were conducted on fluorite to identify all the mineral components and elements distributed into the ore. The methodology involves color macro-and microphotography of unbroken and/or coarsely broken grains. The findings were corroborated to powder x-ray diffraction and fluorescence analyses and electron probe microanalysis to clarify the "annoying" factors (amorphous minerals in clays (slime) fractions, fine dispersion of fluorite, presence of calcite and barite) which could inhibit flotation and, hence, to envisage chages in the processing plant. I NTRODUCTIION The depletion of rich ore deposits, the decrease in the grade and the complexity of the crude ore to be processed have revealed that mineralogical composition of the ore is of fundamental importance in the production of mineral concentrates. Today, no serious mineral processing tests can start without an appropriate knowledge of this feature. Such valuable information can be obtained through the traditional microscopic and particularly thorough microscopic investigations of thin sections and polished specimens. As preparation of thin or polished sections are time consuming, it was found advantageous in the present study to perform macroscopic and microscopic investigations on dispersed grains of the crude ore. Very instructive pictures were taken particularly on daylight and on transmitted or reflected polarized light to disclose the nature and the grain size of individual minerals. The results of these investigations were corroborated and completed by suitable methods of investigation such as powder x-ray diffraction (XRD) and fluorescence (XRF) analyses and electron probe microanalysis (EPMA) of polished ore samples. The performed method offers the possibility to work with a representative sample and to deal with the ore as does the milling process. MATERIALS AND METHODS A waste product of fluorite flotation and 3 others ore samples, "guang feng" (A), "hua tan shan" (B) and "shan hai" (C), containing 86.45%, 87.08% and 89.85% of fluorite (CaF2) respectively were supplied by "Kyoei Chemical Industries" from different chinese mines. As seen in Fig. 1, the crude ore samples were dried, sieved into six fractions +5660, +2000, + 1000, +500, +297 and Fig. 1 Scheme used for mineralogical investigations
Uploads
Papers by Abel Bissombolo