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1

Gravity-based pre-concentration strategies for complex rare earth ore containing niobium and zirconium

Zhou Mingliang, Li Lixia, Liu Feifei, Liu Zhichao, Altun Naci Emre, Yuan Zhitao, Liu Jiongtian

Physicochemical Problems of Mineral Processing

|

2024

|

Vol. 60, iss. 1

art. no. 183609

EN

The Balzhe rare earth mine, renowned for its rich reservoirs of niobium, zirconium, and rare earth elements, poses a unique challenge due to its diverse and interbedded mineral composition. Despite the abundance of these elements, their valuable grade remains notably low, falling short of economic thresholds. To this end, pre-concentration of valuable minerals to discard gangue minerals before flotation would be an economical option. In response, this study delves into the feasibility of gravity-induced pre-concentration, aiming to segregate valuable minerals from gangue for subsequent flotation processes. Conducting float-and-sink tests on varied particle sizes (-2+0.5 mm, -0.5+0.074 mm, and -0.074+0.02 mm) within heavy liquids of specific gravities (ranging from 2.55 to 2.85), the study reveals the effectiveness of gravity separation. Notably, particles sized -2+0.5 mm and -0.074+0.02 mm demonstrated superior separation performance over the -0.5+0.074 mm fraction. Comparative analysis of diverse gravity separation equipment unveiled compelling results. The dense medium cyclone separator showcased impressive recovery rates and high-grade concentrates of Nb2O5, ZrO2, and total rare earth oxides (TREO) at 0.34%, 8.20%, and 0.41%, respectively, surpassing the sand table's performance for -2+0.5 mm particles. Conversely, for -0.5+0.074 mm particles, the shaking table exhibited optimal separation efficiency, yielding grades of Nb2O5, ZrO2, and TREO at 0.37%, 4.08%, and 0.44%, with substantial recovery values. Ultimately, the Knelson centrifugal separator proved most effective for -0.074+0.02 mm particles, yielding notable grades and recoveries of Nb2O5, ZrO2, and TREO. This study underscores the promising potential of gravity-induced pre-concentration techniques for enhancing the recovery of valuable elements from the complex Balzhe rare earth ore, offering critical insights into optimizing mineral extraction processes.

2

Gravity and electrostatic separation of unburned coal from a selected fly ash

Wierzchowski Krzysztof, Klupa Agnieszka, Białecka Barbara, Całus Moszko Joanna

Journal of Sustainable Mining

|

2023

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Vol. 22, iss. 1

33--40

EN

Unburned coal grains make it difficult to use fly ash economically, which causes energy losses in the fuel. The article presents the possibilities of separating unburned coal from selected fly ash. In order to assess the possibility of separation of unburned carbon, the analysis of grain density and ash composition was used. Unburned coal was separated by four methods – one wet gravity and three dry methods. It has been found that despite very fine ash grains, the quality and quantity of separation products are significantly dependent on the separation method used and the separated grains’ qualitative characteristics. The analysis of the coal grains under an electron microscope has revealed that they contain mineral inclusions. Their presence enables selective separation of carbon without first grinding the middling grains. The most advantageous results of the separation of unburned coal were obtained by the electrostatic separation method. Separated coal can be used in high-value carbon applications.

3

Comparison of flash flotation and gravity separation performance in a greenfield gold Project

Erkan Emre, Ekmekci Zafir, Altun Emre

Physicochemical Problems of Mineral Processing

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2022

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Vol. 58, iss. 3

art. no. 146979

EN

Recovery of gold and gold-containing sulfide mineral particles requires multiple-stage recovery processes starting from the grinding circuits to avoid over-grinding of the liberated gold particles. Due to high density, these gold grains tend to follow the hydrocyclone underflow, and a significant amount of metal increases in the circulating load. Therefore, in recent years the grinding circuits have been designed to improve the recovery of free gold/gold-containing particles in the grinding circuit. Gravity separation (centrifugal gravity separators) and flash flotation processes are commonly used for gold recovery in the grinding circuit. This study used a methodology based on modeling-simulation studies to assess various flowsheet configurations involving flash flotation, gravity separation, and the conventional sulfide mineral flotation process. The standard GRG, flash flotation, and rougher kinetic tests were used for the model development of each process. The laboratory tests and simulation studies showed that gold and sulfur recoveries in flash flotation were approximately 7% and 17% higher than that of the gravity separation process. However, the grade of the gravity concentrate was considerably higher. Therefore, one of these unit processes or their combinations can be selected depending on the ore characteristics and the aim of the recovery process. Simulation studies were performed to illustrate the gold recovery performance of various flowsheet configurations. This methodology could be used effectively for flowsheet development, particularly for greenfield projects.

4

Evaluation of the efficiency of metal recovery from printed circuit boards using gravity processes

Franke Dawid M., Suponik Tomasz, Nuckowski Paweł M., Dubaj Justyna

Physicochemical Problems of Mineral Processing

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2021

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Vol. 57, iss. 4

63--77

EN

This paper evaluates the efficiency of metal recovery from printed circuit boards (PCBs) using two gravity separation devices: a shaking table and a cyclofluid separator. The test results were compared with the results obtained from previous research, where an electrostatic separation process was used for an identically prepared feed. The feed for the separators consisted of PCBs shredded in a knife mill at cryogenic temperatures. The separation efficiency and purity of the products were evaluated based on microscopic analysis, ICP-AES, SEM-EDS, XRD, and specific density. The yield of concentrates (valuable metals) obtained from the shaking table and the cyclofluid separator amounted to 25.7% and 18.9%, respectively. However, the concentrate obtained from the cyclofluid separator was characterised by much higher purity, amounting to ~88% of valuable metals, compared to ~72% for the shaking table. In both cases, middlings formed a significant share, their yield amounting to ~25%, with the share of valuable metals of ~15%. The yield of waste obtained from the shaking table and the cyclofluid separator were 42.6% and 52.5%, respectively. In both cases, as a result of the applied process, the waste was divided into two homogeneous groups differing in grain size and shape. The recovery of metals through gravity separation is possible, in particular, by using a shaking table. These processes can also be applied to separate waste (plastics) into two groups to be selectively processed to produce new materials in line with a circular economy.

5

Digital image processing (DIP) application on the evaluation of ironrich heavy mineral concentrates produced from river sand using a sequential mineral processing approach

Terzi Mert, Kursun Ilgin, Cinar Mustafa, Ozdemir Orhan

Physicochemical Problems of Mineral Processing

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2021

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Vol. 57, iss. 3

21--35

EN

In this study, the iron-rich heavy mineral concentrate production from river sand as a byproduct of an alternative resource by gravity, magnetic separation, and flotation methods were investigated in detail. For the physical separation of the sample and increasing the Fe2O3 content, a shaking table and a wet high-intensity magnetic separator were used, respectively. The gravity and magnetic separation experiments included rougher, cleaner, and scavenger circuits. In the flotation experiments, cationic flotation with ethylenediamine under acidic conditions, and anionic flotation with sodium oleate under alkaline conditions were performed. The iron and silica content of the products obtained were determined by digital image processing (DIP) methods and compared with the classical analytical procedures. Finally, a flow chart was proposed for the processing of the ore according to the optimum enrichment parameters were determined from the experiments. The results obtained in this study show that it is possible to produce an iron-rich heavy mineral concentrate with Fe2O3 grade and recovery rate of 79.13% and 57.81%, respectively, in addition to a potential feed for the production of quartz sand and feldspar concentrates.

6

Celestite upgrading by jigs in presence of steel balls as ragging material

Sobhy Ahmed, El-Midany Ayman A., Ibrahim Susan S.

Physicochemical Problems of Mineral Processing

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2021

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Vol. 57, iss. 5

118--128

EN

Gravity separation using jigs is widely used for coarse particle sizes separation. However, fine sizes reduce jig performance. In this study, the upgrading of celestite ore by jig was investigated at different size fractions in the presence of ragging material. Three size fractions, i.e., -15+2 mm, - 2.0 + 0.50 mm and - 0.50 + 0.08 mm were used. The steel balls were used, as ragging material, to improve the separation of fines as well as to improve the concentrate quality. The statistical design was used to correlate celestite grade and recovery with studied operating variables, i.e., the ragging number of layers, ragging balls diameter, and separation time, at a fixed water flow rate and stroke length. The design results indicated that the ragging balls diameter and their number of layers play an important role. The smaller the ragging balls diameter and the higher the ragging number of layers are the better the concentrate grade but the longer the separation time. A celestite concentrate of (> 95% SrSO4) with 74.5% recovery was obtained for - 2.0 + 0.50 mm size fraction at the optimum conditions; i.e., 3.1 mm ragging balls diameter, one ragging layers, and 15 minutes separation time.

7

Cassiterite recovery from a sulfide ore flotation tailing by combined gravity and flotation separations

Zhang Limin, Khoso Sultan Ahmed, Tian Mengjie, Sun Wei

Physicochemical Problems of Mineral Processing

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2021

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Vol. 57, iss. 1

206--215

EN

Cassiterite (SnO2) which is the most important Sn-containing mineral, is extensively found in large quantities in discarded tailings. The recovery of cassiterite from discarded sulfide ore flotation tailings can reduce resource wastage and environmental pollution. The gravity separation technique can recover multiple valuable minerals, such as cassiterite, whose densities considerably differ from those of their associated gangue minerals. However, its recovery efficiency rapidly decreases as the mineral particle grain size decreases. To recover the finer valuable mineral particles from gravity separation tailings, flotation separation can be used as a supplementary method. In this study, the gravity and flotation separation techniques are combined to recover cassiterite from a sulfide ore tailing. The Sn grade and recovery of the final concentrate is 31.40% and 88.05%, respectively, thus indicating a highly efficient recovery of cassiterite by using the combined gravity and flotation separation technique. This study can be an important reference for recovering cassiterite from low-Sn-grade tailings.

8

Mineralogical study and enhanced gravity separation of gold-bearing mineral, South Eastern Desert, Egypt

El-Sayed Samah, Abdel-Khalek N. A., El-Shatoury E. H., Abdel-Motelib A., Hassan M. S., Abdel-Khalek M.A.

Physicochemical Problems of Mineral Processing

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2020

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Vol. 56, iss. 5

839--848

EN

El-Hudi gold deposit, located in the South Eastern Desert of Egypt, represent large vein- type gold occurrence. The representative sample revealed the abundance of quartz as main constituent with minor amounts of mineral impurities. Gold was detectable (12 g/t) as determined using atomic absorption. The petrographic study revealed that the gold grains ranged from 10-40 μm. The grain boundaries of quartz are highly stained with iron minerals as hematite and limonite. Sericite mineral is common in discrete gold-bearing veins. Eroded pyrite was detected with high alteration leaving only cubic-shaped cavities behind. Different techniques for gravity separation were used to separate gold from the quartz mineral. After crushing and grinding of the sample, shaking table was used to upgrade the coarser fractions while Falcon concentrator was employed to upgrade the fine fraction. The best concentrate was obtained through grinding the whole sample to less than 0.2 mm, followed by cleaning steps. The gold content is increased from 12 to 145 g/t with total recovery of 78%.

9

The Proposal of Tungsten Ores Processing in Rwanda

Uwayezu Leader Senga, Mijał Waldemar, Niedoba Tomasz

Inżynieria Mineralna

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2020

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no. 1, vol. 1

161--170

EN

Tungsten is one of the rare elements occurring in Earth. Its applicability and request for it causes that the production of this metal is very beneficial. One of the biggest deposits of this metal ores in the world is located in African country of Rwanda. Due to the lack of appropriate technology and lack of investments the current way of producing this valuable metal in this country causes that much of tungsten is wasted as well the production is slow and the results are not appropriate. That is why an attempt to propose an adequate processing way for this deposit was done and is presented in this paper. Authors performed several tests on the ore originating from Rwanda, including its mineralogical composition and tests performed by means of laboratory shaking table. The results are promising and the further tests, including other methods of beneficiation are planned, like second shaking table stage and flotation.

PL

Wolfram jest jednym z pierwiastków rzadkich występujących na Ziemi. Jego zastosowania oraz zapotrzebowanie świata na ten produkt powodują, że produkcja tego metalu jest bardzo opłacalna. Jedno z największych złóż rudy tego metalu na świecie jest zlokalizowane w afrykańskim państwie, jakim jest Rwanda. Ze względu na brak odpowiedniej technologii oraz brak inwestycji obecny sposób produkcji tego cennego metalu w tym państwie powoduje, że duża ilość wolframu jest tracona, produkcja jest powolna, a wyniki nie są satysfakcjonujące. Dlatego przeprowadzono próbę zaproponowania odpowiedniego sposobu przeróbki tego złoża, która została zaprezentowana w tym artykule. Autorzy wykonali dużo ilość testów przeprowadzonych na rudzie sprowadzonej z Rwandy, włączając w to jej skład mineralogiczny, jak również testy laboratoryjne wzbogacania na stole koncentracyjnym. Wyniki są obiecujące a dalsze testy, włączając w to także inne metody wzbogacania są planowane do przeprowadzenia, biorąc pod uwagę drugi etap wzbogacania na stole koncentracyjnym czy flotację.

10

Współczesne grawitacyjne suche metody wzbogacania ziaren drobnych

Mijał Waldemar

Przegląd Górniczy

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2019

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T. 75, nr 6

36--40

PL

Od początku XXI wieku można zaobserwować wzrost zainteresowania suchymi metodami wzbogacania węgla, jak i innych surowców mineralnych. Można tutaj wymienić typowe wzbogacanie w osadzarce powietrznej poprzez zastosowanie pulsacji powietrznej (osadzarki TFX, osadzarka Allair), wzbogacanie w separatorach powietrznych z wykorzystaniem złoża fluidalnego (wibracyjno-powietrzny separator typu FGX), wzbogacalniki powietrzne zawiesinowe (wzbogacalniki AMFB) czy separację optyczną wykorzystującą różnicę np. w kolorze poszczególnych ziaren (separatory OSX, CXR). Jednak większość z nich nie osiąga dokładnej separacji ziaren drobnych według ich gęstości. W zależności od typu urządzenia dotyczy to ziaren o wymiarach od 13 do 6 mm. W artykule przedstawiono wybrane rozwiązania konstrukcyjne nowoczesnych urządzeń do wzbogacania ziaren drobnych na sucho oraz porównanie ich wyników.

EN

From the beginning of the twenty-first century we can observe an increase interest in the dry beneficiation method related for coal as well and other mineral resources. The typical enrichment in an air jig can be mentioned here by using air pulsation (TFX jigs, Allair jig), air table fluidization using a fluidized bed (vibrating FGX air table), suspension air enrichments (AMFB enrichments) or optical separation using the difference eg in color of individual grains (OSX, CXR separators). However, most of them have a problem in the form of fine separation of fine grains and depending on the type of device, the limit is below 6-13 mm. The article will present the possibilities of individual new technological solutions used in the world and will present the benefits of using dry separation of mineral raw materials, in particular coal.

11

Coal Middlings Recycling – a Route for Increasing the Yield of Sellable Concentrate

Korolev I.

Inżynieria Mineralna

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2018

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R. 19, nr 1

159--164

EN

Because of the low quality, middlings from the coal preparation often remain unused and are stored on the industrial site or simply landfilled. The authors offer a possible solution to this problem; its main idea is to upgrade the flowsheet of the coal processing plant by recycling the by-product that will turn it into valuable concentrate. Such approach would increase the efficiency of processing, allow comprehensive utilization of mineral raw materials, reduce the loss of combustible matter from coal with rejects, and would result in higher revenue from the sales of high-quality coal concentrate. This article represents outcomes of the studies of coarse coal middlings as potential raw material for producing sellable concentrate. The middlings are obtained from a coal preparation plant located in Kuznetsk coal basin, Russia. Samples have been crushed down to a size of 13 mm, and then a float-sink analysis has been completed from which the liberation degree is calculated. Performance of gravity separation and flotation of slimes has been evaluated with a laboratory scale equipment. It is shown that middlings of the coking coal have high potential to yield a high-quality concentrate. Forecasted mass balance of the proposed flowsheet for the middlings reprocessing shows that 50 to 80% of total middlings production might be transformed into low-ash coal concentrate.

PL

Ze względu na niską jakość, półprodukty z wzbogacania węgla często pozostają niewykorzystane i są przechowywane na terenach przemysłowym lub po prostu składowane na składowisku. Autorzy proponują rozwiązanie problemu wykorzystania przerostów; główną ideą jest modernizacja schematu technologicznego zakładu przeróbki węgla poprzez wzbogacanie produktu pośredniego, który pozwoli uzyskać koncentrat handlowy. Takie podejście zwiększy wydajność przeróbki, pozwala na kompleksowe wykorzystanie surowców mineralnych, ograniczają straty substancji palnej z węgla i będą generować wyższe przychody ze sprzedaży wysokiej jakości koncentratu węgla. W artykule przedstawiono wyniki badań półproduktów z wzbogacania węgla kamiennego jako potencjalnego surowca do produkcji koncentratu handlowego. Zakład wzbogacania jest zlokalizowany w Zagłębiu Kuźnieckim w Rosji. Próbki zostały rozdrobnione do wielkości 13 mm, a następnie przeprowadzono analizę densymetryczną i poddano separacji grawitacyjnej i flotacji w warunkach laboratoryjnych. Wykazano, że półprodukty z przeróbki węgla koksowego mają duży potencjał do uzyskania wysokiej jakości koncentratu. Prognozowany bilans masowy proponowanego schematu dla wtórnego wzbogacania półproduktów pokazuje, że 50 do 80% całkowitej ilości półproduktów można wzbogacić w celu uzyskania koncentratu węgla o niskiej zawartości popiołu.

12

Ocena wzbogacalności flotacyjnej rudy złota

Krawczykowska A.

Inżynieria Mineralna

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2017

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R. 18, nr 1

221--226

PL

W artykule przedstawiono wyniki wzbogacania rudy złota. Do badań wykorzystano dwie próbki rudy, znacznie różniące się zawartością tego pierwiastka. Zostały one poddane operacjom przygotowawczym, polegającym głównie na głębokim rozdrobnieniu i klasyfikacji. Porównano wyniki wzbogacania flotacyjnego próbek w dwóch różnych układach wzbogacania: bezpośrednio po rozdrobnieniu oraz po wstępnym wzbogaceniu na stole koncentracyjnym. Flotacja okazała się efektywną metodą wzbogacania badanej rudy, uzyskane koncentraty cechują się wysokimi zawartościami złota, natomiast w odpadach pozostały śladowe jego ilości. Ponadto analiza wyników wykazała, że wprowadzenie wzbogacania grawitacyjnego przed procesem flotacji wpłynęło pozytywnie na jakość flotowanych koncentratów.

EN

The article presents the results of gold ore beneficiation process. Two samples of ore, significantly differed in terms of gold content, were utilized for investigations. Samples were subjected the preparatory operations, consisting of fine comminution and classification. There were compared the results of flotational beneficiation obtained in two different processing circuits: directly after grinding and after pre-concentration operation with using the shaking table. The flotation operation has proven to be an effective method of concentration for this type of ore, the obtained concentrates were of a high gold grade, while the gold contents in tails were very low. In addition, the analysis of the results showed that application of gravity concentration prior to flotation process positively influenced the quality of flotation concentrates.

13

Badanie wpływu kąta nachylenia płyty roboczej stołu koncentracyjnego na przebieg procesu wzbogacania drobnych ziaren węglowych

Manowska A., Mazurek M.

Przegląd Górniczy

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2016

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T. 72, nr 10

18--23

PL

W artykule przedstawiono wyniki badań wzbogacania drobnych ziaren węgla surowego na stole koncentracyjnym. Analizowano wpływ zmiany kąta nachylenia płyty roboczej stołu na wartość użytkową otrzymanych produktów rozdziału. Badania przeprowadzone w skali laboratoryjnej pokazały, iż przy odpowiednim doborze kąta nachylenia można uzyskać koncentraty węglowe o zawartości popiołu rzędu kilku do kilkunastu procent, jak i odpady przekraczające 80% popiołu. Drugim etapem pracy była analiza statystyczna przeprowadzonych badań laboratoryjnych, która udowodniła prawidłowość przeprowadzonego procesu oraz zależności pomiędzy parametrami technologicznymi stołu a uzyskanymi produktami wzbogacania.

EN

The article presents results of researches of fine coal particles enrichment on the concentration table. As a point of reference there was chosen the effect of the angle of adjustment of the platen table on the utility value of obtained products. Researches have shown that the proper selection of the technological parameter of the table that was the inclination angle, allows to get coal concentrates from a few to a dozen per cent and waste exceeding 80% of the ash by preventing the loss of useful particles that have a certain energy potential. In the second part of the article there appeared static analysis of laboratory studies that have proved the correctness of the performed process, and the dependencies between process parameters table and the obtained products of enrichment.

14

Study on pre-concentration efficiency of wolframite from tungsten ore using gravity and magnetic separations

Lu D., Wang Y., Jiang T., Sun W., Hu Y.

Physicochemical Problems of Mineral Processing

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2016

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Vol. 52, iss. 2

718--728

EN

Pre-concentration is effectively applied in recovering wolframite from tungsten ore, due to its benefits of further upgrading tungsten ore and improving separation efficiency. The most important pre-concentration techniques for tungsten ore include gravity separation and magnetic separation, based on the fact that there are appreciable differences, between the desired wolframite and the gangue minerals, in density and magnetic susceptibility. This study investigated the separation efficiency of gravity pre-concentration (Falcon Concentrator) and high-gradient magnetic pre-concentration (SLon VPHGMS) for the beneficiation of a Canada tungsten ore. It is a low-grade type of ore with high silica and arsenic content, and an average content of WO3 is about 0.45%. The optimum conditions for different operational parameters of two pre-concentration separators were studied on this low-grade material. The results presented in this paper suggested that although both pre-concentration techniques were effective for producing pre-concentrates containing high WO3, magnetic pre-concentration showed significantly better separation efficiency. Over 90% of the feed was rejected as the final tailings, meanwhile, over 85% of arsenic minerals were removed with tailings, while the WO3 loss was less than 15%.

15

The effects of sonication on gravity separation of waste activated sludge

Kamizela T., Kowalczyk M., Malińska K

Inżynieria i Ochrona Środowiska

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2015

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T. 18, nr 2

155--167

EN

Sonication applied to different phases of wastewater and sewage sludge treatment can be beneficial in many respects. The work reported in the literature is mostly focused on sonication as a disintegration process. However, sonication is also used for conditioning of biological sludge. Disintegrating and conditioning effects of ultrasonic waves depend on the value of specific energy. The aim of the presented work was to perform the analysis of solid/liquid separation of waste activated sludge that was subjected to sonication. The properties and structure of activated sludge changed due to the exposure to ultrasounds. This resulted in some changes in the process dynamics of sedimentation and compression. The results showed that sonication accelerated the process of settling and enhanced compression of the particles. However, thickened sludge obtained by gravity separation showed low dewaterability. Gravitational separation of activated sludge subjected to sonication caused a problem with contamination of the obtained supernatant. The increase in the ultrasounds specific energy resulted in cyclical deterioration in the quality of the supernatant. The concentration of organic substance was as high as for municipal wastewater. As a result the liquid with significant quantities of solid particles can be used as growing medium for microorganisms due to increased biodegradability. Moreover, due to the sonication a layer of suspended sludge is formed. This layer consists of a large number of particles that are not subject to sedimentation. Also, this layer sustains biological activity of living organisms. It is proposed to use activated sludge sonication within separate technological system of gravitational separation. The supernatant and thickened sludge obtained from gravity separation can be considered as valuable products. The observed effects of sonication depended on the following variables: the amplitude of ultrasonic wave and specific energy. It was found that generally there are no significant differences in the observed effects of sonication for different amplitudes required to maintain stable values of specific energy. Sonication effects can be described by mathematical functions (linear regression) that allow the control of ultrasonic treatment.

PL

Dotychczasowe doświadczenia laboratoryjne wskazują, że proces sonifikacji można wykorzystywać niemalże na każdym etapie oczyszczania ścieków i przeróbki osadów. W większości przypadków sonifikację traktuje się jako metodę dezintegracji, w tym dezintegracji osadów nadmiernych kierowanych do komór fermentacyjnych. Sonifikacja może być również wykorzystana jako czynnik kondycjonujący osady ściekowe. Dezintegracyjne bądź kondycjonujące oddziaływanie fali ultradźwiękowej jest silnie uzależnione od energii wprowadzonej do sonifikowanego medium. Celem przedstawionej pracy była analiza efektywności separacji grawitacyjnej sonifikowanej zawiesiny osadu czynnego. Widocznym efektem nadźwiękawiania osadu czynnego było rozbicie struktury kłaczków. Rezultatem sonifikacji były również silne zmiany w dynamice procesu sedymentacji oraz kompresji cząstek. Odnotowano znaczące zwiększenie prędkości sedymentacji cząstek oraz skrócenie czasu zagęszczania. Uzyskane osady zagęszczone charakteryzowały się jednak ograniczoną podatnością na odwadnianie. Kolejną wadą rozdziału grawitacyjnego sonifikowanych zawiesin było pogorszenie jakości cieczy nadosadowych. Stężenia zanieczyszczeń w cieczy nadosadowej odpowiadały charakterystyce jakościowej dopływających do oczyszczalni ścieków komunalnych. Zdaniem autorów uzyskane produkty rozdziału grawitacyjnego można rozpatrywać jako łatwobiodegradowlane substraty dla biocenozy osadu czynnego. Ciecze nadosadowe można scharakteryzować jako łatwo biodegradowalny substrat organiczny. Ponadto cząstki stałe pozostające w cieczy nadosadowej tworzą stan zawieszonego osadu czynnego. Powstaje w ten sposób specyficzna warstwa filtracyjna, zachowująca aktywność biologiczną. Miejsce zastosowania niskoenergetycznej sonifikacji, takiej jak w zrealizowanych badaniach, widzi się jako proces prowadzony w wydzielonym ciągu technologicznym opartym na zagęszczaczu osadów sonifikowanych. Uzyskane produkty rozdziału grawitacyjnego o wysokiej podatności na biodegradację, tj. ciecze nadosadowe oraz osady zagęszczone, można dozować do reaktorów osadu czynnego. Obserwowane efekty oddziaływania fali ultradźwiękowej zależały od badanych parametrów operacyjnych, tj. amplitudy drgań oraz właściwej energii sonifikacji. Stwierdzono, że na ogół nie ma znaczących różnic w zaobserwowanych efektach w zależności od wielkości zastosowanej amplitudy przy stałej wielkości energii sonifikacji wprowadzonej do osadów. Drugi wniosek wypływający z analizy matematycznej dotyczy możliwości opisu zmian wartości badanych parametrów w funkcji zwłaszcza właściwej energii sonifikacji za pomocą regresji liniowej.

16

Characterization and beneficiation of iranian low-grade manganese ore

Mehdilo A., Irannajad M., Hojjati-Rad M. R.

Physicochemical Problems of Mineral Processing

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2013

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Vol. 49, iss. 2

725--741

EN

The mineralogical studies indicated that the Charagah ore deposit contains approximately 17% pyrolusite, 78% calcite and 3–4% quartz. Pyrolusite as a main valuable mineral is found in the forms of coarse and fine pyrolusites. The coarse grains pyrolusite with simple texture is liberated at 180 micrometers. Another kind of pyrolusite with particle size finer than 10 m is disseminated inside gangue phases. This kind of pyrolusite has important effect in beneficiation processes and can affect the manganese grade of the concentrate and its recovery negatively. By jigging machine a pre-concentrate with 20% MnO and a final tailing with about 13% manganese loss are obtained. Using tabling technique or wet high intensity magnetic separation (WHIMS) and also their combination with jigging machine, production of a final pyrolusite concentrate with suitable grade but average recovery is possible. By jigging-tabling a concentrate with – 500+45 m size fraction, 44.3% MnO and 61.3% recovery is obtained while jigging-WHIMS produces a concentrate containing 52.6% MnO with a recovery up to 56.6% and d80 = 180 m.

17

Gravity concentration of sudanese chromite ore using laboratory shaking table

Seifelnasr A. A., Tammam T., Abouzeid A. Z. M.

Physicochemical Problems of Mineral Processing

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2012

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Vol. 48, iss. 1

271-280

EN

The main raw materials for chromium metal is chromite. Geologically, chromite deposits are associated, by their nature of formation, with specific gangue minerals such as serpentine, olivine, and chlorite. These associated minerals are of lower densities than chromite. This criterion of density difference between chromite and the associated minerals suggests the use of gravity separation techniques for concentrating the low-grade chromite ores. This paper presents the results of an investigation on the concentration of a low-grade (30% to 35% Cr2O3) chromite ore from Chickay Mine, East of Sudan, using a shaking table. The studied parameters were the table tilt angle and the feed size distribution. The optimum table tilt angle was 6?, and the best performance of the table was obtained when the feed was split into two size fractions, -1.168 + 0.18 mm and - 0.18 mm, without desliming. The concentrate assay, under these conditions, was 47.2% Cr2O3 at a recovery of 75 percent.

18

Analysis of selected methods of beneficiating coal slurries deposited in impoundments

Szpyrka J., Lutynski M.

Physicochemical Problems of Mineral Processing

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2012

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Vol. 48, iss. 2

579-589

EN

The paper presents research results of the possibility to beneficiate coal slurries deposited in 21 impoundments located in the region of Silesia, Poland. Coal slurries of particle size diameter below 1 (0.5) mm were subjected to beneficiation tests with the use of the following methods: centrifugal separator, hydrocyclone, Reichert spiral separator and flotation. Applied methods showed significant differences in obtained results. The most effective method was flotation where yield was on average 64% with concentrate of high calorific value. In case of centrifugal separator and Reichert type spiral average yield was 22% and 25%, respectively. In case of hydrocyclone classifier-separator, a high yield of low quality concentrate was obtained. The study revealed that such impoundments have a high energetic potential which can be effectively used by applying a proper beneficiation technology.

19

Badania odzysku składników użytecznych z odpadów flotacyjnych przy użyciu separatora wirówkowego Knelsona

Potulska A.

Prace Naukowe Instytutu Górnictwa Politechniki Wrocławskiej. Konferencje

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2005

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Vol. 110, nr 42

341-353

PL

Wykonano eksperymenty wzbogacania grawitacyjnego odpadów flotacyjnych z przeróbki rud miedzi z nieczynnego osadnika "Gilów" w Lubinie. W badaniach użyto laboratoryjnego separatora firmy Knelson, w którym rozdział ziarn dokonuje się w polu działania siły odśrodkowej w strumieniu wody skierowanym w kierunku przeciwnym działaniu tej siły. Głównym parametrem operacyjnym stosowanego separatora jest ciśnienie strumienia wody doprowadzanej do płaszcza wodnego wirującego elementu roboczego. Eksperymenty prowadzono dla trzech różnych klas ziarnowych: 0,250 - 0,500, 0,125 - 0,250 i < 0,125 mm przy różnych ciśnieniach wody fluidyzacyjnej. Postawą oceny otrzymanych produktów były oznaczenia zawartości frakcji minerałów ciężkich przy użyciu cieczy ciężkich. Dokonano analizy przebiegu wzbogacalności badanych klas ziarnowych materiału . Stwierdzono, ze najlepsze wyniki wzbogacania otrzymano dla najdrobniejszej klasy ziarnowej - 0,125mm, sumaryczny uzysk minerałów ciężkich dla tej klasy wyniósł 75,8 %. Z badanego materiału udało się wydzielić koncentrat zawierający 51 % minerałów ciężkich.

EN

Laboratory tests using Knelson gravity separator were conducted on flotation tailings form the old Polish tailing pound "Gilow". Experiments were carried out for three different particle size 0.250 - 0.500, 0.125 - 0.250 and < 0.125 mm. In Knelson separator the water pressure is the main operating parameter. During tests various values of that parameter were tested. To analyze the content of received products heavy media separation were performed. The content of heavy minerals were established, and upgrading analysis in each particle size have been carried out during the experimental work. The best results were achieved for the finest material < 0.125 mm, where the cumulative recovery of heavy minerals reached the value of 75.8% with a non cumulative grade in one of the concentrates in the same size equals 51%.

20

Wpływ własności geometrycznych ziarn na dokładność rozdziału w cieczach ciężkich zawiesinowych

Brożek M., Turno A.

Gospodarka Surowcami Mineralnymi

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2004

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T. 20, z. 3

85-99

PL

Każdy rzeczywisty proces rozdziału w skali przemysłowej zachodzi w warunkach ruchu turbulentnego. Z tego względu poszczególne produkty rozdziału zawierają ziarna o własnościach spoza przedziału własności charakterystycznych dla tego produktu. Ilościowo efekt ten ujmuje funkcja rozdziału, która w przypadku wzbogacania grawitacyjnego określa ułamek frakcji o gęstości /ro trafiającej do jednego z produktów rozdziału, w odniesieniu do ilości tej frakcji w nadawie. Dokładność rozdziału jest w praktyce przemysłowej mierzona rozproszeniem prawdopodobnym lub imperfekcją. W warunkach ruchu turbulentnego wartość rozproszenia prawdopodobnego jest uwarunkowana przez czynniki związane z własnościami geometrycznymi ziarn nadawy, charakterystyką urządzenia oraz parametrem technologicznym procesu. Zmiennymi charakteryzującymi własności geometryczne ziarna są średnica sitowa ziarna oraz jego kształt. W pracy przedstawiono wyniki badań nad wpływem własności geometrycznych ziarn, takich jak wielkość oraz kształt ziarna, na dokładność rozdziału w cieczach zawiesinowych charakteryzowaną przez rozproszenie prawdopodobne.

EN

Each real separation process in industrial scale takes place in turbulent conditions of motion. Therefore particular separation products include particles with properties from beyond interval of properties typical for this product. Quantitatively the partition function decracts yhis effect, which determines, in the case of gravity separation, the fraction's fragment of the density r getting to the one of separation products, in relation to the quantity of this fraction in the feed. In industrial practice, the separation efficiency is estimated by probable error or imperfection. In turbulent conditions of motion, the value of probable error is conditioned by factors connected with the geometric properties of the feed particles, device characteristics and technological parameters of the process. The variables, which characterize the particles geometric properties are screen particle diameter and the particle shape. This paper presents results of the investigations on influence of the particles geometric properties such as: the influence of size and shape of the particle on separation efficiency in dense media, being characterized by probable error.