Transfer of Gold, Platinum and Non-Ferrous Metals from Matte to Slag by Flotation

One of the stages of extracting gold and platinum from sulfide materials and circulating slags is the melting stage in ore-thermal and electric furnaces, where the melt is separated into matte and slag. Gold, platinum, and non-ferrous metals are concentrated in the matte. However, a significant portion of them ends up in the slag, which reduces recovery and increases environmental pollution. The main reason for their transition to slag is the flotation of sulfide droplets by gas bubbles, a significant proportion of which occurs during the decomposition of sulfides. Gold and platinum are associated with matte droplets during flotation. Evaluation of adhesion showed that it is large and comparable to the cohesion of these metals. One of the options to reduce the loss of valuable components is to add fluxes to the slag. The influence of calcite and fluorite on the distribution of gold and platinum over the melting products of copper–nickel sulfide materials (matte and slag) has been experimentally studied based on the above theoretical concepts of droplet flotation. When calcite was added to sulfide ore, there was a significant decrease in the sulfur content in the slag (more than 3 times). This, in turn, led to a decrease in non-ferrous metals in the slag by 2–3 times, with gold from 0.45 to 0.29 g/t and platinum from 2.15 to 2.06 g/t. The addition of fluorite to the mixture of copper–nickel matte and model slag (CaO/SiO2/Al2O3 = 40/40/20) significantly reduced the sulfur content and non-ferrous metals by 1.5 times, whereas gold was not found in the slag. The decrease in the number of sulfides in the slag is mainly because the listed additives reduce its viscosity. This leads to acceleration of the coagulation of sulfide drops, which are inevitably carried into the slag during flotation, and increases the rate of their settling to the slag–matte boundary, where they merge with the matte mass.

Assessment of the Soft-Tissue Seal at the Interface between the Base of the Fixed Denture Pontic and the Oral Mucosa

Fixed dentures (bridges) are often selected as a treatment option for a defective prosthesis. In this study, we assess the contact condition between the base of the pontic and oral mucosa, and examine the effect of prosthetic preparation and material biocompatibility. The molars were removed and replaced with experimental implants with a free-end type bridge superstructure after one week. In Experiment 1, we assessed different types of prosthetic pre-treatment: (1) the untreated control group (Con: mucosa recovering from the tooth extraction); (2) the laser irradiation group (Las: mucosa recovering after the damage caused by a CO2 laser); and (3) the tooth extraction group (Ext: mucosa recovering immediately after the teeth extraction). In Experiment 2, five materials (titanium, zirconia, porcelain, gold-platinum alloy, and self-curing resin) were placed at the base of the bridge pontic. Four weeks after the placement of the bridge, the mucosa adjacent to the pontic base was histologically analyzed. In Experiment 1, the Con and Las groups exhibited no formation of an epithelial sealing structure on the pontic base. In the Ext group, adherent epithelium was observed. In Experiment 2, the sealing properties at the pontic interface were superior for titanium and the zirconia compared with those made of porcelain or gold-platinum alloy. In the resin group, a clear delay in epithelial healing was observed.

Abnormally high content of noble metals in wastes of the Fiagdon concentration plant: a possible new type of mineralization for the North Caucasus is gold-platinoid with base metals, localized in the Early-Middle Jurassic black shales

На Северном Кавказе благороднометалльное (золото, серебро, платина, элементы платиновой группы) оруденение черносланцевого типа локализовано в тоар-ааленских флишоидных углеродсодержащих терригенных отложениях, приуроченных к региональной Самуро-Белореченской металлогенической зоне (СБМЗ) – от Дагестана до Адыгеи и Краснодарского края. Вовлечение в поисково-разведочные работы этого стратегического минерального типа оруденения дает возможность расширить минерально-сырьевую базу Южного федерального округа России. Цель исследований – выявление содержаний благородных металлов и элементов платиновой группы (ЭПГ) в промышленных отходах Фиагдонской обогатительной фабрики (ФОФ) и в рудовмещающих тоар-ааленских черносланцевых толщах. ФОФ, в частности, перерабатывала руды полиметаллических месторождений Кадат и Какадур, локализованных в тоар-ааленских флишоидных углеродсодержащих терригенных отложениях Авсандур-Ламардонского рудного поля (АЛРП). Проведена оценка АЛРП на возможность выявления здесь промышленно значимого золото-платиноидного с полиметаллами оруденения в черносланцевой толще. Методы исследования. ICP-MS анализом проанализированы 5 проб в Центре «ИГЕМ-Аналитика» на масс-спектрометре X-Series IIи 13 проб – в Лаборатории физико-химических и химических методов анализа ИМГРЭ на приборе Elan 6100 DRC. Результаты работы. Установленные в 18 пробах (в керне скважин) Фиагдонского хвостохранилища (ФХ) повышенные содержания благородных металлов можно объяснить наличием как в рудах АЛРП, так и во вмещающей их нижне-среднеюрской углеродсодержащей песчано-глинистой флишоидной толще нового для Северного Кавказа нижне-среднеюрского золото-платиноидного cполиметаллами оруденения в черносланцевой толще (2,5-3,2 мас. % УГВ). Предложена модель образования золото-платинового оруденения черносланцевого типа за счет конвекции вадозных вод в высоко металлоносных (Au, Ag, Pt, Pd) ранне-среднеюрских флишоидных толщах алевролито-аргиллитового состава. При поисковых работах на золото-кварцевый, золото-сульфидный и колчеданно-полиметаллический с золотом типы оруденения в Горной Осетии и в восточной части Горного Дагестана был выявлен ряд перспективных на золото объектов.В пределах СБМЗ может быть выявлен ряд промышленно значимых объектов с золото-платиноидным с полиметаллами оруденением в черносланцевых толщах тоар-ааленского возраста. Предложен комплекс мероприятий с минимальными временными, материальными и финансовыми затратами. In the North Caucasus noble-metal (gold, silver, platinum, elements of the platinum group (PGE)) mineralization of the black-shale type is localized in Toar-Aalenian flysch-like organic matter rich, terrigenous sediments in the regional (from Dagestan to Adygea and Krasnodar Territory) Samuro-Belorechenskaya metallogenic zone (SBMZ). Involvement in prospecting and exploration of this strategic type of mineralization provides the opportunity to expand the mineral resource base of the Southern Federal District of Russia. The Aim of the research is to identify the content of platinum and PGE in the industrial wastes of the Fiagdon concentration plant (FCP) and in the ore-bearing Toar-Aalenian black shale strata. In particular, processed ores of the Kadat and Kakadur polymetallic deposits, localized in Avsandur-Lamardon ore field (ALOF). The ALRP was prospected for economic gold-platinum with polymetallic deposit in the black-shales series. Methods. ICP-MS analysis - 5 samples were analyzed by ICP-MS in IGEM-Analytics Center on an X-Series II mass spectrometer and 13 samples - in the Laboratory of Physical-Chemical and Chemical Methods of Analysis of the IMGRE on the Elan 6100 DRC instrument. Results. The elevated noble metal concentrations established in 18 samples (borehole core samples) from the Fiagdon tailings dump could be explained by the presence of both the ALRP ores and the gold-platinum with polymetallic mineralization in the host Toar- Aalenian black-shales series (2.5-3.2 wt. % of carbonaceous matter). The model of formation of gold-platinum mineralization at the expense of vadose water convection in highly metalliferous (Au, Ag, Pt, Pd) Early-Middle Jurassic flysch-like strata of siltstone-argillite composition is proposed. During prospecting works for gold-quartz, gold-sulfide and colliery-polymetallic with gold types of mineralization in the Mountain Ossetia and in the eastern part of Mountain Dagestan a number of promising objects for gold were revealed. A number of economic significant objects with gold-platinum with polymetallic mineralization in black-shale series of Toar-Aalenian age can be identified within the SBMZ. A complex of prospecting with minimal time, material and financial expenses is proposed

Rapid controlled synthesis of gold–platinum nanorods with excellent photothermal properties under 808 nm excitation

Noble metal nanomaterials are particularly suitable as photothermal transduction agents (PTAs) with high photothermal conversion efficiency (PCE) due to local surface plasmon resonance (LSPR). Studies on different gold–platinum (Au–Pt) bimetal nanoparticles exhibiting the LSPR effect have provided a new idea for the synthesis of excellent PTAs. But there is no simple and scalable method for the controllable synthesis of Au–Pt nanoparticles with adjustable LSPR wavelength range. In this work, the effects of Ag+ and K2PtCl4 on the deposition of Pt on the surface of gold nanorods (AuNRs) were investigated. A fast, precise, and controlled synthesis of dumbbell-like Pt-coated AuNRs (Au@Pt NRs) under mild conditions is proposed. The synthesized Au@Pt NRs have a longitudinal LSPR wavelength of 812 nm, which is very close to a common laser wavelength of 808 nm. The Au@Pt NRs exhibit excellent photothermal properties when irradiated with a laser. The temperature increased by more than 36 °C after irradiation for 10 min, with a PCE of about 78.77%, which is much higher than that of AuNRs (57.33%). In addition, even after four on/off cycles, the Au@Pt NRs are able to maintain the photothermal properties and retain their optical properties, indicating that they have excellent photothermal stability and reusability.

KAJI ULANG SNI 13-3487-2005 BARANG – BARANG EMAS DAN SNI 13-3771-1995 BARANG – BARANG EMAS MUDA

<p>Emas merupakan logam mulia yang dapat dijadikan investasi karena nilainya terus naik dari waktu ke waktu. Barang – barang emas dapat berbentuk batangan, granula, lembaran, perhiasan dan benda seni. Penjaminan mutu kadar emas diatur dalam SNI 13-3487-2005 Barang – barang emas dan SNI 13-3771-1995 Barang – barang emas muda. Pada saat ini emas yang beredar memiliki kadar mulai 3,33% hingga 99,99% (<em>fine gold</em>). Terdapat nilai kadar emas yang belum diatur dalam ke-dua SNI tersebut yaitu barang-barang emas dengan kadar 13,14,15,dan 16 karat. Sehingga perlu dilakukan pengujian untuk melihat kesesuaian kadar emas yang terkandung dalam barang – barang emas yang beredar di pasaran serta peninjauan kembali terhadap metode uji yang ada. Penelitian ini membahas hasil kaji ulang SNI 13-3487-2005 Barang – barang emas dan SNI 13-3771-1995 Barang – barang emas muda sebagai dasar penyusunan SNI barang – barang emas yang baru. Metode penelitian yang dilakukan adalah studi literatur, pengujian sampel barang – barang emas yang beredar yang diambil secara <em>purposive sampling</em>, kemudian dilakukan pengujian <em>fire assay</em> sesuai dengan SNI 13-3487-2005 Barang – barang emas dan ICP-OES sesuai dengan ISO 15093, <em>Jewellery — Determination of precious metals in 999 0 / 00 gold, platinum and palladium jewellery alloys</em> — <em>Difference method using ICP-OES</em>, kajian metode uji, dan penggalian informasi melalui rapat internal, rapat teknis dan rapat konsensus. Berdasarkan pembahasan maka dapat disimpulkan bahwa perlunya penggabungan dua SNI tersebut mencakup kadar 33,3% hingga 99,99%, menetapkan metode uji yang dipergunakan yaitu <em>fire assay</em> dan ICP-OES, dengan acuan normatif yang dipergunakan adalah standar ISO 11596 dan ISO 15039.</p>