Effect of Thiourea Containing Composite Additives on Nickel Electrodeposition in Ammoniacal Solution

Composite additives have an important influence on the process of metal electrodeposition and the quality of a metal deposited layer. In this work, the additive thiourea (TU) was compounded with cetyltrimethyl ammonium chloride (CTAC), sodium dodecyl sulfate (SDS) and polyethylene glycol 20,000 (PEG20000), and their effect on the cyclic voltammetric behavior, electrochemical nucleation mechanism, crystallographic orientations and surface morphology of the nickel electrodeposition in ammoniacal solution were experimentally investigated. The results show that the introduction of composite additives resulted in a stronger cathodic polarization and increased the nucleation overpotential (NOP) values significantly, which had an important impact on forming compact and smooth nickel deposits. The chronoamperometry analysis indicated that the reduction in nickel followed the 3D progressive nucleation mechanism in the presence of composite additives at the step potential of −1.16 V and −1.18 V. Smoother and finer nickel films were found using scanning electron microscopy (SEM) images as the composite additives were used. X-ray diffraction revealed that all nickel deposit samples had the face-centered cubic structure, and five main crystal planes were displayed by the presence of composite additives in the electrolyte. Furthermore, the diffraction peaks of (111) and (200) crystal planes were slightly shifted toward lower 2θ values when thiourea was used in combination with additive CTAC or PEG20000. These results were beneficial for understanding the mechanisms and facilitating the rational design of additives for metal nickel electrodeposition.

Efficiency of Ni Content in Laterite Nickel Deposits through The Least Square Method Approach on Semivariogram

Ordinary kriging is one of the geostatistical techniques used for spatial prediction on a spatially distributed random plane. Ordinary kriging is a linear unbiased estimator which is part of a semivariogram system of equations that minimizes errors of variance in estimating mineral resources. The semivariogram model shows optimal results in the estimation using the least square method, the effective minimization method smoothes the data points against the curve on a semivariogram graph, the least square makes the size error efficient in the semivariogram model and has been proven to be effective in reducing errors in the semivariogram model in the case of laterite nickel deposits. at PT. Vale Indonesia Tbk. Thus, conclusively the prediction of unsampled Ni content results is very accurate. This is indicated by the lowest root mean square error (RMSE) in limonite in the exponential model, saprolite in the spherical model, and bedrock in the gaussian model. The greatest value of Ni content in this study was in the saprolite layer.

Fitting the variogram model of nickel laterite using root means square error in Morowali, Central Sulawesi

Abstract. The nickel commodity is getting popular due to its role as one of the raw materials for battery manufacture. It is estimated that this trend will continue for the next 2 - 3 years and reaching its peak when the factories that process the raw material for electric vehicle batteries are established. For this reason, the nickel mining companies are competing to explore new nickel deposits. The research location is a nickel mine in Sulawesi. The purpose of this study was to determine the most suitable Nickel variogram model based on root means square error (RMSE). To obtain an accurate number of resources, it is necessary to apply an accurate and validated estimation method to gain data that are in line with the actual conditions. Therefore, this study uses a geostatistical method that takes into account the spatial relationship of each data using a variogram which is validated by the cross-validation method and RMSE. From the results of the RSME analysis, the most suitable variogram model for nickel content in the limonite and saprolite layers is the exponential variogram model. In addition, the values of root mean square error for nickel content in the limonite and saprolite layers were 0.022 and 0.098 respectively.

Forecasting criteria for sulphide PGE-copper-nickel deposits of the Noril’sk province (In English)

Research subject. World-class sulphide platinum-group-element (PGE)-Cu-Ni deposits occur within the Noril’sk-Talnakh region of northern Siberia, Russia. The signifcance of these deposits presents opportunities to determine the most effective approaches for the search of similar deposits using commercial PGE-Cu-Ni deposit examples. Materials and methods. Petrological and geochemical analysis of the ultramafc-mafc intrusions of the Noril’sk province ranks them into three types in terms of sulphide mineralization style and economic signifcance: 1) economic intrusions containing unique and large sulphide PGE-Cu-Ni deposits (Oktyabr’sk, Talnakh and Noril’sk-1); 2) subeconomic intrusions that contain small- to medium-sized Cu-Ni sulphide deposits, and medium-sized to large PGE deposits (Chernogorsk, Zub-Marksheider, Vologochan, etc.); 3) uneconomic intrusions that contain low-grade disseminated Cu-Ni ores with ≈0.2 wt % of Cu and Ni, and low Cr and PGE (Nizhny Talnakh, Zelyonaya Griva, etc.). Results and conclusions. Principal sources used in exploration for rich sulphide PGE-Cu-Ni ores include structural, magmatic, stratigraphic-lithological, geochemical, mineralogical, metamorphic and some others. Based on an analysis of isotope-geochemical data, new indicators for locating sulphide PGE-Cu-Ni mineralization are suggested. A restricted range of S-isotope values, and a negative trend for coupled S-Cu isotope compositions can be employed as useful guides to assess the economic potential of a PGE-Cu-Ni sulphide deposit. It is proposed that the Chernogorsk ultramafc-mafc intrusion of the Noril’sk province is the most promising target in a search for rich PGE-Cu-Ni ores. It is suggested that the previously known mineralogical-geochemical and novel isotope-geochemical characteristics of sulphide and silicate minerals are important indicators in assessing the potential ore content of ultramafc-mafc intrusions of the Noril’sk province.

Influence of mechanical deflector assisted electroless nickel deposits for wear resistance

This investigation reports the effect of mechanical deflector during coating on the mechanical properties of the Electroless Ni-P deposits. Micro hardness of the electroless Ni-P deposits was measured using shimadzu micro hardness measuring unit employing a diamond indenter and pin-on-disc wear tester was used to measure the wear resistance of the deposits. The characteristics of deposits produced in presence of mechanical deflector are found to be superior from those produced using conventional deposition techniques. Enhancement in properties are correlated with modified crystallinity and the conversion of Ni-P in to possible phosphides in the presence of mechanical deflector. It has been noticed that the coating efficiency has 30% hike with mechanical deflector. Annealing at 350ºC has reached the maximum hardness of 950 Hv and subsequent increase in wear resistance.

Electrodeposition and Corrosion Properties of Nickel–Graphene Oxide Composite Coatings

Nickel-based composite electrochemical coatings (CEC) modified with multilayer graphene oxide (GO) were obtained from a sulfate-chloride electrolyte in the reverse electrolysis mode. The microstructure of these CECs was investigated by X-ray phase analysis and scanning electron microscopy. The corrosion-electrochemical behavior of nickel–GO composite coatings in a 0.5 M solution of H2SO4was studied. Tests in a 3.5% NaCl solution showed that the inclusion of GO particles into the composition of electrolytic nickel deposits makes their corrosion rate 1.40–1.50 times less.

Profile of Laterite Nickel Deposits, at Tinanggea District, South Konawe Regency, Southeast Sulawesi Province

The research area is located in Tinanggea District, South Konawe Regency, Southeast Sulawesi Province. This study aims to determine the profile of laterite nickel deposits in the study area. The research method used consists of literature study, field sampling and laboratory analysis and data interpretation. The results showed that the profiles of laterite nickel deposits in the study area consisted of top soil, limonite zone, saprolite zone and bedrock with different thicknesses. Top soil at Station 1 is very thin in the form of clay and plant remains, while at Station 2 it is a layer of sediment (limestone) with a thickness of 0-5 meters. Based on geochemical data, it shows that Ni, SiO and MgO elements /oxides show enrichment in the saprolite zone because have mobile so its dissolve easily during the laterization process and are transported the subsurface and experience leaching so that its are concentrated in the saprolite zone. The Fe element shows enrichment in the limonite zone because the Fe element has immobile so that it is not easily transported downward and is concentrated in the upper zone, namely the limonite zone.

Сульфидные медно-никелевые месторождения в срединных массивах Пиренейского полуострова и Камчатки

A comparative description of two sulfide copper-nickel deposits confined to the middle massifs is given: Aguablanca (Iberian Massif, Spain) and Shanuch (Kamchatka Massif, Russia). It was shown that both deposits are spatially and genetically related to small intrusions and dikes of mostly basic composition. Ore bodies are funnel-shaped, lenticular, stock-shaped, and vein-like, and are spread to significant depths. Both deposits contain rich sulfide copper-nickel ores as well as relatively poor; the ore texture is predominantly breccia or massive, seldom disseminated. Ore mineral composition includes pyrrhotite, pentlandite, and chalcopyrite with an insignificant admixture of minerals of the platinum group elements and gold. The ore bodies were topped with an "iron hat", which was the main sign of copper-nickel mineralization at depth.

Hubungan Pola Penyebaran dan Ketebalan Zona Bijih Endapan Nikel Laterit dengan Topografi Permukaan Pada PT Aneka Tambang Tbk

Abstrak: Indonesia merupakan negara yang memiliki sumber daya nikel laterit yang berlimpah, mulai dari Sulawesi hingga ke Papua. Oleh karena itu, peneliti melakukan analisis pola sebaran dan ketebalan endapan nikel leterit untuk mendapatkan pola sebaran zona bijih dari endapan nikel laterit berdasarkan topografi permukaan. Adapun metode yang dilakukan adalah menganalisis sampel pemboran dengan X-ray spectometer, menganalisis topografi, morfologi dan membuat profil penampang antar sumbu bor untuk menganalisis pola sebaran zona bijih endapan nikel laterit. Data yang dihasilkan dari penelitian ini adalah bentuk topografi perbukitan dengan morfologi bergelombang, miring hingga melandai, dengan kemiringan lereng 20-160. Penampang endapan secara vertikal mengunakan parameter overburden dengan kadar Ni < 0.90% – > 4%. Penampang serta pola sebaran endapan nikel laterit terbagi 3 warna yaitu coklat untuk kadar Ni < 0.90%, kuning untuk kadar Ni 0,91% – 1,50%, dan hijau untuk kadar Ni > 1,51%. Berdasarkan penampang korelasi pada topografi landai, didapatkan kadar yang tinggi serta tebal dan topografi yang berbukit miring ditemukan kadar yang tinggi tetapi ketebalan yang tipis. Secara keseluruhan kadar nikel laterit berkisar 8 – 16 meter. Kata Kunci: Topografi, Nikel Laterit, Kadar, Ketebalan, Pola Penyebaran Abstract: Indonesia is a country that has abundant nickel laterite resources, from Sulawesi to Papua. Therefore, the researchers analyzed the distribution pattern and thickness of the nickel leterite deposits to obtain the distribution pattern of the ore zones of the laterite nickel deposits based on the surface topography. The method used is to analyze the drilling sample with an X-ray spectometer, analyze the topography, morphology and create a cross-sectional profile between the drill axes to analyze the distribution pattern of the laterite nickel ore deposit zone. The data generated from this study is a hilly topography with a wavy morphology, slanted, and sloping, with a slope of 20-160. The vertical cross section of the sediment uses overburden parameters with Ni content < 0.90% – > 4%. The cross-section and distribution pattern of laterite nickel deposits are divided into 3 colors, namely brown for Ni content < 0.90%, yellow for Ni content 0.91% – 1.50%, and green for Ni content > 1.51%. Based on the cross-sectional correlation on the sloping topography, it was found that high grades and thick and hilly topography found high grades but thin thicknesses. Overall, laterite nickel content ranges from 8 to 16 meters. Keywords: Topography, Nickel Laterite, Grade, Thickness, Distribution Pattern