scholarly journals The Role of Gangue Mineralogy on Flowsheet Development in Fluorite Processing

Minerals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 237
Author(s):  
Jestos Taguta ◽  
Kebone Carol Teme ◽  
Portia Ngobeni
Keyword(s):  
Froth Flotation ◽  
Raw Material ◽  
Energy Costs ◽  
Flotation Process ◽  
Pulp Temperature ◽  
Caf2 Content ◽  
Flowsheet Development ◽  
Optimum Production ◽  
High Quartz

Fluorite, CaF2, is considered a strategically important mineral as it is a raw material for many strategic industries. Froth flotation is reported to be the most efficient and economically viable process for the production of an acid-grade product with a CaF2 content of at least 97%. Selective flotation of fluorite from gangue minerals, e.g., calcite and barite, is challenging because these minerals have similar physicochemical properties. This study employed batch flotation tests coupled with mineralogical analysis to design suitable customised flowsheets and efficiently optimised reagent regimes for optimum production of acid-grade fluorite concentrate from two different fluorite ores by the froth flotation process. The effect of pulp temperature on fluorite flotation was investigated in this study with the objective of lowering pulp temperatures in fluorite flotation. The results showed that an acid-grade CaF2 concentrate could be obtained from the flotation of both ores at ambient pulp temperatures. This eliminates the requirement for high-temperature pulp treatment, which would result in a significant reduction in thermal energy costs. This study showed that an understanding of gangue mineralogy is key to process optimisation for acid-grade CaF2 production. Although an acid-grade CaF2 concentrate could be produced from both ores, the flowsheets and reagent regimes were markedly different. For instance, the production of an acid-grade CaF2 product from a high quartz and calcite ore was achieved by employing a simple rougher–multiple cleaner flotation circuit using tannin and sodium silicate as calcite and quartz depressants, respectively. On the other hand, the production of an acid-grade CaF2 product from the flotation of the pyritic ore required a pre-sulphide flotation stage for upfront sulphur removal and the use of a sulphide depressant. Multiple stages of cleaning were required for improved selectivity in the flotation of both ores.

scholarly journals Parachute structure trisiloxane surfactant: synthesis and its use in reverse flotation of iron ore

2021 ◽  
Author(s):  
Zhiqiang Huang ◽  
Shiyong Zhang ◽  
Vladimir E. Burov ◽  
Hongling Wang ◽  
Rukuan Liu ◽  
...  
Keyword(s):  
Density Functional ◽  
Chemical Reactivity ◽  
Froth Flotation ◽  
Density Functional Theory Calculations ◽  
Raw Material ◽  
Mulliken Charge ◽  
Single Element ◽  
Test Results ◽  
Functional Theory ◽  
Flotation Process

Abstract No single element has exerted such a deep influence on social organization of mankind as iron. Magnetite is concentrated by froth flotation and used as a raw material to produce iron. However, the conventional surfactants used in the flotation process often lead to the weak collecting performance due to their analogous alkyl hydrophobic group. Here, we report a new trisiloxane surfactant N-(β-aminoethyl)-γ-aminopropyltrisiloxane (AAT) in magnetite flotation, which was compared with the traditional collector dodecylamine (DA). The flotation test results showed that AAT had excellent collecting ability and selectivity for quartz against magnetite. Magnetite concentrate with TFe recovery of 84.79%, TFe grade of 68.84% and SiO2 grade of 6.15% was obtained by using 150 g/t AAT. Density functional theory calculations suggested reactive site of AAT was cationic –CH2N+H3 group, and AAT showed a higher positive grouping Mulliken charge and chemical reactivity that may promote its flotation performance.

scholarly journals Rheological Characterization of a Concentrated Phosphate Slurry

Fluids ◽  
2021 ◽  
Vol 6 (5) ◽  
pp. 178
Author(s):  
Souhail Maazioui ◽  
Abderrahim Maazouz ◽  
Fayssal Benkhaldoun ◽  
Driss Ouazar ◽  
Khalid Lamnawar
Keyword(s):  
Flow Behavior ◽  
Continuous Phase ◽  
Raw Material ◽  
Rheological Characterization ◽  
Phosphate Ore ◽  
Insoluble Particles ◽  
Experimental Protocols ◽  
Solid Liquid

Phosphate ore slurry is a suspension of insoluble particles of phosphate rock, the primary raw material for fertilizer and phosphoric acid, in a continuous phase of water. This suspension has a non-Newtonian flow behavior and exhibits yield stress as the shear rate tends toward zero. The suspended particles in the present study were assumed to be noncolloidal. Various grades and phosphate ore concentrations were chosen for this rheological investigation. We created some experimental protocols to determine the main characteristics of these complex fluids and established relevant rheological models with a view to simulate the numerical flow in a cylindrical pipeline. Rheograms of these slurries were obtained using a rotational rheometer and were accurately modeled with commonly used yield-pseudoplastic models. The results show that the concentration of solids in a solid–liquid mixture could be increased while maintaining a desired apparent viscosity. Finally, the design equations for the laminar pipe flow of yield pseudoplastics were investigated to highlight the role of rheological studies in this context.

112 How Will the Purebred Association Adapt to a Changing Beef Industry?

2021 ◽  
Vol 99 (Supplement_1) ◽  
pp. 39-39
Author(s):  
Mark McCully
Keyword(s):  
Supply Chains ◽  
Genetic Information ◽  
Gene Editing ◽  
Value Added ◽  
Beef Industry ◽  
Breed Improvement ◽  
Pull Through ◽  
Optimum Production ◽  
Selection Tools

Abstract The role of the breed association has historically been to keep a registry of a pure breed, aggregate the performance data surrounding that one breed, develop breeding and selection tools, and conduct breed promotion. Larger associations have been able to augment that with operating magazines and other media, running branded beef programs, feeder calf marketing programs, and genetic evaluation for other breeds. The relevance of breed associations is being and will continue to be challenged as genomics and large commercial databases develop and allow for breeding and selection tools to be developed independently by large breeders or private entities. Gene editing and other such technology will also challenge the traditional seedstock models and opens the door for proprietary genetic lines. Breed associations may need to modify their traditional policies to incorporate these innovations. Supply chains will continue to become far more sophisticated and will incorporate more genetic information to guide management decisions and potentially validate brand promises around sustainability. To stay relevant, breed associations of the future will need to do the following: Balance the needs of diverse membership (show, hobby, lifestyle, etc.) with commercial industry value and significance. Have access to large amounts of data and be leaders in adopting the most current technologies. Deliver tools for breeders that enhance the profitability of commercial producers – identify optimum production levels vs maximum outputs. Work collaboratively with multiple supply chains providing the needed genetic information. Be a significant educational resource to breeders and commercial producers. Be a leader in research on breed improvement and genetic advancement. Have value-added programs that create real and sustained pull-through demand for the end product.

scholarly journals Contribution of Cyanotoxins to the Ecotoxicological Role of Lichens

Toxins ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 321
Author(s):  
Dobri Ivanov ◽  
Galina Yaneva ◽  
Irina Potoroko ◽  
Diana G. Ivanova
Keyword(s):  
Research Methods ◽  
Raw Material ◽  
Modern Times ◽  
Effective Application ◽  
The World ◽  
The Common

The fascinating world of lichens draws the attention of the researchers because of the numerous properties of lichens used traditionally and, in modern times, as a raw material for medicines and in the perfumery industry, for food and spices, for fodder, as dyes, and for other various purposes all over the world. However, lichens being widespread symbiotic entities between fungi and photosynthetic partners may acquire toxic features due to either the fungi, algae, or cyano-procaryotes producing toxins. By this way, several common lichens acquire toxic features. In this survey, recent data about the ecology, phytogenetics, and biology of some lichens with respect to the associated toxin-producing cyanoprokaryotes in different habitats around the world are discussed. Special attention is paid to the common toxins, called microcystin and nodularin, produced mainly by the Nostoc species. The effective application of a series of modern research methods to approach the issue of lichen toxicity as contributed by the cyanophotobiont partner is emphasized.

Ivory in the Chalcolithic enclosure of Perdigões (South Portugal): the social role of an exotic raw material

2015 ◽  
Vol 47 (3) ◽  
pp. 390-413 ◽  
Author(s):  
António Carlos Valera ◽  
Thomas Xaver Schuhmacher ◽  
Arun Banerjee
Keyword(s):  
Social Role ◽  
Raw Material ◽  
The Social ◽  
South Portugal

A true gift of mother earth: the use and significance of obsidian at Çatalhöyük

2011 ◽  
Vol 61 ◽  
pp. 1-19 ◽  
Author(s):  
Tristan Carter
Keyword(s):  
Raw Materials ◽  
Daily Practice ◽  
Social Identities ◽  
Raw Material ◽  
Central Anatolia ◽  
Social Significance ◽  
Key Issues ◽  
Raw Material Variability ◽  
Mother Earth

AbstractThis paper reviews 50 years of obsidian studies at Neolithic Çatalhöyük in the Konya plain, central Anatolia. A number of key issues are addressed: (1) the source of the site's raw materials, the means and forms by which the obsidian was introduced to the site and the role of Çatalhöyük in the supra-regional dissemination of these raw materials; (2) the alleged gender associations of certain obsidian goods in the burial record and beyond; (3) a more general consideration of the social significance of the circulation and consumption of obsidian at the site, including the phenomena of hoarding and gifting, plus the important role of projectiles in the creation of social identities and various forms of ritual behaviour, not least the termination of the life of a building/individual; (4) the technotypological and raw material variability through time; (5) the use of obsidian in daily practice and craft-working.

Development of 3D Printing Technology with Ceramic Paste and Study of Properties of Printed Corundum Products

2021 ◽  
Vol 1040 ◽  
pp. 178-184
Author(s):  
Andrey S. Dolgin ◽  
Aleksei I. Makogon ◽  
Sergey P. Bogdanov
Keyword(s):  
3D Printing ◽  
Aluminum Oxide ◽  
Reference Sample ◽  
Physical And Mechanical Properties ◽  
Ceramic Technology ◽  
Raw Material ◽  
Energy Costs ◽  
Additive Technology ◽  
X Ray ◽  
Manufacturing Time

Today 3D printing with ceramics is a promising direction in the development of additive technologies. In this work, we have developed a technology for printing with ceramic pastes based on aluminum oxide and wax, namely: an extruder for printing with ceramic pastes was modeled and manufactured, the composition of the slip was selected and the paste for printing was made. After choosing the print parameters, test samples were printed: a disk and a box. Since 3D printing with ceramics is just one of the stages of manufacturing ceramic products, then we selected the parameters for drying and sintering the raw material. Drying of products is necessary to burn off an excess amount of a binder (paraffin), and due to sintering; the raw material acquires final strength and mechanical characteristics. After sintering, the sintering parameters and physical and mechanical properties of the products were measured. The microstructure of the printed products was studied using scanning electron microscopy. The phase change during sintering was studied by X-ray analysis. All obtained properties were compared with a reference sample (corundum tile made of aluminum oxide of the same grade, but using traditional ceramic technology, including pressing, drying and sintering of the product). In terms of all properties, the printed ceramics are not significantly inferior to the reference sample; however, in general, the additive technology has more advantages, such as a wide variety of shapes, shorter manufacturing time for parts, and lower energy costs.

scholarly journals Les Clubs de presse au Japon

2019 ◽  
Vol 8 (2) ◽  
pp. 124-137
Author(s):  
César Castellvi
Keyword(s):  
Division Of Labor ◽  
Career Path ◽  
Raw Material ◽  
Television Channel ◽  
Geographical Mobility ◽  
Media Companies ◽  
Daily Press ◽  
Club Membership ◽  
Exclusive Right

    FR. En partant de l’analyse des clubs de presse japonais, cet article porte sur le rôle joué par les entreprises médiatiques dans les relations des journalistes aux sources institutionnelles. En tant que principale forme d’accès aux sources, les clubs de presse (kisha kurabu) sont des rassemblements de reporters accrédités aux institutions majeures de la société (ministères, administrations, grandes entreprises, commissariats). Ils se distinguent d’autres formes d’associations de journalistes par leur présence systématique à l’ensemble du pays ainsi que par leur modalité d’accès. Seuls les reporters salariés d’une entreprise de la presse quotidienne ou d’une chaîne de télévision peuvent y adhérer. Cela écarte les autres segments de la profession et impose une division du travail où les reporters salariés disposent seuls de l’exclusivité sur la production d’informations institutionnelles. Ce système, souvent critiqué, mais toujours en place, s’explique également par l’organisation des carrières des journalistes. Les parcours des reporters salariés se déroulent en interne des entreprises et sont soumis à une forte mobilité thématique et géographique. Cette mobilité rend difficile l’entretien d’un carnet d’adresses pour beaucoup d’entre eux. L’accréditation aux clubs joue le rôle de facilitateur de mise en relation avec les sources. En contrepartie, il renforce la dépendance des journalistes vis-à-vis des entreprises qui sont les véritables propriétaires de l’accès à la matière première de l’information.   ***   EN. Based on an analysis of Japanese press clubs, this paper examines the role of media companies in journalists' relations with institutional sources. Press clubs (kisha kurabu) consist of reporters accredited by the major institutions of society (ministries, administrations, large companies, police stations) and are the main avenue of access to these sources. They differ from other journalists' associations in their systematic presence throughout the country and how one becomes a member. Only reporters employed by a daily press company or television channel can join. This bars access by other segments of the profession and imposes a division of labor in which staff reporters have the exclusive right to produce institutional news. This system is often criticized, and yet it persists, at least in part because of the career path of journalists, which takes place within companies and are subject to high thematic and geographical mobility. This mobility makes it difficult for many of them to maintain a roster of sources. Club membership facilitates connection with sources. In return, it reinforces journalists' dependence on companies that are the true gatekeepers of access to the raw material of news.   ***   PT. Partindo da análise dos clubes de imprensa japoneses, este artigo enfoca o papel desempenhado pelas empresas de mídia nas relações dos jornalistas com as fontes institucionais. Como principal forma de acesso às fontes, os clubes de imprensa (kisha kurabu) são reuniões de repórteres credenciados em grandes instituições da sociedade (ministérios, administrações, grandes empresas, delegacias de polícia). Distinguem-se de outras formas de associação de jornalistas por sua presença sistemática em todo o país e por sua modalidade de acesso. Somente repórteres que são funcionários de uma empresa de jornais diários ou de um canal de televisão podem participar. Isso exclui outros segmentos da profissão e impõe uma divisão do trabalho em que apenas os repórteres assalariados têm direitos exclusivos sobre a produção de informações institucionais. Esse sistema, frequentemente criticado, mas ainda em vigor, também é explicado pela organização de carreiras de jornalistas. As jornadas dos repórteres assalariados são realizadas internamente pelas empresas e estão sujeitas a uma alta mobilidade temática e geográfica. Essa mobilidade dificulta a manutenção de um catálogo de endereços para muitos deles. O credenciamento de clubes atua como um facilitador para o vínculo com as fontes. Em contrapartida, reforça a dependência dos jornalistas de empresas que são os verdadeiros proprietários do acesso à matéria-prima da informação.   ***

scholarly journals The Status and the Role of ‘Chocolate’ Silicite in the Bohemian Neolithic

2018 ◽  
Vol 56 ◽  
pp. 49-64
Author(s):  
Pavel Burgert
Keyword(s):  
Social Status ◽  
Raw Materials ◽  
Raw Material ◽  
Carpathian Mountains ◽  
Or Groups ◽  
The Status ◽  
Czech Lands ◽  
Image Expansion

The article focuses on the chronological status of the distribution of ‘chocolate’ silicite originating from the area of south-east Poland in the prehistory of the Czech lands. The flow of ‘chocolate’ silicite across the Carpathian Mountains culminated in the period of the Stroke-Ornamented Ware culture (5100/5000–4500/4400 cal BC) in the area studied. Based on the analysis of the contexts of finds and the classification of the artefacts, the raw material is interpreted as an indicator of the presence of individuals or groups with an exclusive social status. Both the pattern of distribution and the status are common to other ‘exotic’ raw materials, especially for Carpathian obsidian, in the studied area in that same period. By comparing the spatial and chronological image expansion of both materials can lead to similar conclusions in their assessment

scholarly journals LOW- GRADE STRUCTURES OF NOBLE AND NON- FERROUS METALS AND METHODS OF THEIR SELECTIVE SEPARATION

2021 ◽  
Vol 13 (2) ◽  
pp. 161-169
Author(s):  
Tatyana ALEXANDROVA ◽  
◽  
Anastasia AFANASOVA ◽  
Nadezhda NIKOLAEVA ◽  
◽  
...  
Keyword(s):  
Development Strategy ◽  
Raw Materials ◽  
Close Association ◽  
Mining Industry ◽  
Raw Material ◽  
Free Form ◽  
Mineral Matter ◽  
Low Grade ◽  
Rare Metals ◽  
Flotation Process

There is a worldwide trend of increasing the share of extraction and processing of low-grade minerals, but their extraction and processing volumes are still low. There are several reasons for this: high mining and transportation costs, imperfect techniques and technological difficulties in enrichment and processing of refractory and low-quality minerals. Due to the depletion of reserves of easily beneficiated raw materials and to compensate for the growing shortage of high-quality minerals, the Russian mining industry development strategy provides for the involvement of new and unconventional types of deposits into production. Examples of such deposits are deposits of carbonaceous raw materials (black shale, refractory sulphide carbon-bearing ores, impactites, etc.) containing carbon of varying degrees of metamorphism. On the basis of the most modern mineralogical, physical, nuclear and chemical methods of research of composition, structure and properties of the carbonaceous raw materials at the micro- and nanolevel, the composition of the productive mineral matter, physical, chemical and thermodynamic laws of separation of valuable mineral components and the basic technological processes to obtain the finished product for valorization of the unconventional carbonaceous mineral raw materials were determined with maximum reliability. One of the possible reasons of difficulty of beneficiation of carbonaceous raw materials is the fine phenocrysts in graphite which can be solved by using the flotation process. Contrast of surface properties of minerals with similar technological properties can be increased by application of different energy effects (MEMI, MIO, microwave, electrochemical treatment etc.) at successive stages of raw material transformation, regulation of pulp conditioning conditions (duration and intensity of agitation, heat treatment of pulp) as well as by development and application of selective reagent regimes. The special feature of flotation as a method of extraction of noble and rare metals is the ability to extract valuable metals not only in their native free form, but also in close association with sulphides and carbon. Flotation with the use of intensifying influences made it possible to transfereven low-sized structures of noble and rare metals, which are not extracted by conventional methods of cyanidation, gravitation enrichment and amalgamation, into the concentrate. One of the ways to increase the efficiency of the flotation process is preliminary modification of the additive which is introduced in addition to the main reagents of the sinter - “carrier material”.

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