Study of One Sort of Romanian Diatomite as Precursor in the Synthesis of Some Metallic Silicates

2008 ◽  
Vol 59 (6) ◽  
Author(s):  
Dan Macarovici ◽  
Viorel Paraschiv ◽  
Elisabeth-Jeanne Popovici
Keyword(s):  
Calcium Carbonate ◽  
Magnesium Oxide ◽  
Alkaline Earth ◽  
Thermal Reaction ◽  
Calcium Silicates ◽  
Magnesium Silicates ◽  
Calcium And Magnesium ◽  
Alkaline Earth Silicates

The behaviour of one sort of Romanian diatomite as precursor in the synthesis of calcium and magnesium silicates was studied. The calcination of this diatomite, 3 h at 10000C in air, does not produce major modifications in structure and composition. In the same conditions, the thermal reaction between diatomite and calcium carbonate leads to a mixture of calcium silicates (CaSiO3, Ca2SiO4, Ca3SiO5) whereas the reaction product with magnesium oxide is orthomagnesium silicate (Mg2SiO4 - forsterite). This sort of Romanian diatomite can play the same role as other silica sources in the synthesis of alkaline-earth silicates.

Study of the Process of Heavy Metals Cations Mineralization by Poly-Component Structures Based on Calcium and Magnesium Silicates

2020 ◽  
Vol 989 ◽  
pp. 103-109
Author(s):  
Tatiana M. Lonzinger ◽  
Vadim A. Skotnikov ◽  
Alexey M. Sukharev
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Heavy Metal Ions ◽  
Environmental Pollutants ◽  
Acidic Environment ◽  
Copper Zinc ◽  
Calcium Silicates ◽  
Magnesium Silicates ◽  
Calcium And Magnesium ◽  
Leaching Reaction

In order to achieve the goal of absorption of environmental pollutants, poly-component materials based on magnesium and calcium silicates - metal cations mineralizers – have been synthesized. The study of the processes of mineralization was carried out using model solutions containing soluble sulphates of copper, zinc, manganese and iron. The studies carried out have shown that the synthesized mineralizer based on calcium and magnesium silicates has a multicomponent structure with active electrochemically inhomogeneous centres on its surface as a result of breaking the Ca-O-Si, Mg-O-Si bonds, hydration and leaching of the Ca2+ and Mg2+ ions. In an acidic environment, the leaching reaction is activated due to H+ adsorption and the weakening of the bond between Ca2+ and O2-, thus making the transition of Ca2+ into the liquid phase more advantageous. As a result, a negatively charged ≡Si-O-layer enriched with silicon is formed, which is able to interact chemically with heavy metal ions present in the electrolyte solution.

scholarly journals Water Quality and Calcium plus Magnesium Fertilization Effects on Container-Grown Gardenia and Japanese Holly

1987 ◽  
Vol 5 (2) ◽  
pp. 49-52
Author(s):  
D.L. Brosh ◽  
C.E. Whitcomb ◽  
S.W. Akers ◽  
P.L. Claypool
Keyword(s):  
Water Quality ◽  
Calcium Carbonate ◽  
Magnesium Oxide ◽  
Visual Grade ◽  
Gardenia Jasminoides ◽  
Calcium And Magnesium ◽  
Container Nurseries ◽  
Fertilization Effects ◽  
Irrigation Waters ◽  
Quality Measurements

Combinations of calcium carbonate with magnesium oxide were found to be superior to dolomite as calcium and magnesium fertilizers for container production of gardenia (Gardenia jasminoides ‘Radicans’) and Japanese holly (Ilex crenata ‘Convexa’). When growth and quality measurements were analyzed, a number of significant water quality by fertilizer interactions were found for both species. In contrast, when responses to water quality and to different rate combinations of calcium carbonate and magnesium oxide (no dolomite) were analyzed, only the visual grade of gardenias showed a significant water quality by fertilizer interaction. Since calcium and magnesium are common constituents of irrigation waters, it is suggested that commercial container nurseries test different rate combinations of calcium carbonate and magnesium oxide for their own water supply and plant species of importance.

Production of Primary Magnesium by the Aluminothermic Reduction of Magnesia Extracted from Dolomite Ore

2014 ◽  
Vol 788 ◽  
pp. 28-33
Author(s):  
Peng Deng ◽  
Yu Qin Liu ◽  
Wen Gui Yao ◽  
Hong Wen Ma
Keyword(s):  
Calcium Carbonate ◽  
Magnesium Oxide ◽  
Vacuum Condition ◽  
Reduction Ratio ◽  
Raw Material ◽  
Aluminothermic Reduction ◽  
Molar Ratio ◽  
New Process

In this paper, a new process for the production of the primary magnesium is introduced using the dolomite as the raw material. The magnesia and calcium carbonate were prepared from dolomite by acidification. The content of magnesium oxide can reach 98.92% about the magnesia obtained. The magnesia is used to produce primary magnesium by aluminothermic reduction under vacuum condition. The reduction ratio of MgO can be up to 86.14% under the temperature of 1200°C for 5hrs, briquetting pressure of 10MPa and the molar ratio of MgO to Al of 3:2. The content of magnesium is more than 99.90%. The major phases in the briquette residue are corundum and spinel, which can be used as refractory.

Minimization of Anthropogenic Impact on the Environment of Waste of Mining Complex by Recycling Them in the Soil Concrete Modified with Natural Zeolites

2020 ◽  
Vol 24 (6) ◽  
pp. 24-29
Author(s):  
N.A. Konovalova ◽  
O.N. Dabizha ◽  
P.P. Pankov ◽  
E.A. Rush
Keyword(s):  
Construction Industry ◽  
Anthropogenic Impact ◽  
Raw Materials ◽  
Natural Zeolites ◽  
Modern Methods ◽  
Mass Fractions ◽  
Mining Complex ◽  
Magnesium Silicates ◽  
Calcium And Magnesium ◽  
Chemical And Phase Compositions

The article considers the possibility of reduction of anthropogenic impact on ecosystems of various levels of waste of mining complex by their largetonnage direct using in the construction industry. The methods of utilization of waste crushed production modified with natural zeolites and stabilizing additive in the composition of soil concrete are studied. The chemical and phase compositions of the inital mineral raw materials and soil concrete based on them are studied by a complex of modern methods. Optimal mass fractions of clinoptilolite rock (5–15 wt. %) and a polymeric stabilizing additive (1 wt. %) allowing to obtain composites with a maximum strength grade of 100 (М 100) are established. The increase of strength characteristics of soil concrete modified with zeolite-containing rock is associated with an increase of their density by the presence of crystalline calcium and magnesium silicates in the structure as well as the filling of the interparticle space with mineral and polymer additives.

Nickel Loss during Iron Precipitation and Product Characterization

2011 ◽  
Vol 402 ◽  
pp. 293-296
Author(s):  
Kai Wang ◽  
Jian Li ◽  
R.G. McDonald ◽  
R.E. Browner
Keyword(s):  
Calcium Carbonate ◽  
Magnesium Oxide ◽  
Precipitation Process ◽  
Nickel Sulphate ◽  
Temperature Range ◽  
Iron Precipitation ◽  
Product Characterization ◽  
Ph Range ◽  
Iron Precipitates

In this study, the iron precipitation and associated nickel loss from synthetic ferric and nickel sulphate solutions were investigated. Two types of common neutralizing agents, magnesium oxide and calcium carbonate were applied in the investigation. The results indicated that pH and temperature had significant impacts on nickel loss during the iron precipitation process, whereas the type of neutralizing agents had little effect. It was found that increasing in pH and temperature resulted in more nickel loss in the pH range of 2 to 4 and temperature range of 25 to 85 °C. Mineralogical examination by XRD indicated that the iron precipitates were combinations of schwertmannite, ferrihydrite and goethite. In addition, more crystalline goethite was formed from the ferric solutions when no nickel was present, indicating that nickel might play a role in inhabiting the crystallization of goethite.

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