scholarly journals Effect of Pre-Wetting of High-Silica Sand on Parameters of Dried Moulding Sands Bonded with Selected Grades of Water-Glass

2016 ◽  
Vol 16 (2) ◽  
pp. 454-460
Author(s):  
Mateusz Stachowicz ◽  
Kazimierz Granat ◽  
Łukasz Pałyga ◽  
Michał Kamiński
Keyword(s):  
Water Glass ◽  
Silica Sand ◽  
High Silica

scholarly journals Prediction of Properties of Microwave- Hardened Sandmixes Containing Water- Glass with Use of Neural Networks

2015 ◽  
Vol 15 (2) ◽  
pp. 99-104
Author(s):  
M. Stachowicz ◽  
Ł. Pałyga ◽  
K. Granat
Keyword(s):  
Neural Networks ◽  
Artificial Neural Networks ◽  
Microwave Heating ◽  
Water Glass ◽  
Silica Sand ◽  
Heating Process ◽  
Technological Parameters ◽  
High Silica ◽  
Artificial Neural ◽  
Process Trial

Abstract Presented are results of a research on the possibility of using artificial neural networks for forecasting mechanical and technological parameters of moulding sands containing water-glass, hardened in the innovative microwave heating process. Trial predictions were confronted with experimental results of examining sandmixes prepared on the base of high-silica sand, containing various grades of sodium water-glass and additions of a wetting agent. It was found on the grounds of obtained values of tensile strength and permeability that, with use of artificial neural networks, it is possible complex forecasting mechanical and technological properties of these materials after microwave heating and the obtained data will be used in further research works on application of modern analytic methods for designing production technology of high-quality casting cores and moulds.

scholarly journals Research on Reclamation and Activation of Moulding Sands Containing Water-Glass Hardened with Microwaves

2014 ◽  
Vol 14 (2) ◽  
pp. 105-110 ◽  
Author(s):  
M. Stachowicz ◽  
K. Granat
Keyword(s):  
Water Glass ◽  
Silica Sand ◽  
Subsequent Stage ◽  
Activation Process ◽  
Technological Properties ◽  
Scanning Microscope ◽  
Screen Analysis ◽  
Inorganic Binder ◽  
High Silica

Abstract Presented are results of a research on usability of an innovative reclamation process of microwave-hardened moulding sands containing water-glass, combined with activation of binder. After each subsequent stage of reclamation, quality of the reclaimed material was determined on the grounds of measurements of permeability and results of screen analysis. The reclaimed material was next used again to prepare new moulding sand. The sandmix based on high-silica sand prepared with water-glass grade 145, was subject to the following cyclical treatment operations: mixing components, consolidation, microwave hardening, cooling, heating the mould up to 800 °C, cooling to ambient temperature, mechanical reclamation dry and wet. It was found that the used-up and reclaimed sandmix containing water-glass is susceptible to the applied activation process of thermally reacted film of binder and, in addition, it maintains good quality and technological properties of high-silica base. Observations of surfaces of reclaimed high-silica grains with activated film of reacted inorganic binder were carried-out using a scanning microscope. Thanks to properly selected reclamation parameters, the high-silica base can be reused even five times, thus reducing demand for fresh aggregate and inorganic binder.

scholarly journals Evaluation of the Possibilities of Sodium Silicate Sands Application in Automated Hot-Box Process of Cores Shooting

2017 ◽  
Vol 17 (4) ◽  
pp. 155-160
Author(s):  
M. Stachowicz ◽  
K. Granat ◽  
P. Obuchowski
Keyword(s):  
Sodium Silicate ◽  
Bending Strength ◽  
Heating Temperature ◽  
Heating Time ◽  
Silica Matrix ◽  
Silica Sand ◽  
Operating Parameters ◽  
High Quality ◽  
High Silica ◽  
Preliminary Research

AbstractThe paper presents the results of preliminary research on the use of silica sands with hydrated sodium silicate 1.5% wt. of binder for the performance of eco-friendly casting cores in hot-box technology. To evaluate the feasibility of high quality casting cores performed by the use of this method, the tests were made with the use of a semiautomatic core shooter using the following operating parameters: initial shooting pressure of 6 bar, shot time 4 s and 2 s, core-box temperature 200, 250 and 300 °C and core heating time 30, 60, 90 and 150 s. Matrixes of the moulding sands were two types of high-silica sand: fine and medium. Moulding sand binder was a commercial, unmodified hydrated sodium silicate having a molar module SiO2/ Na2O of 2.5. In one shot of a core-shooter were made three longitudinal samples (cores) with a total volume of about 2.8 dm3. The samples thus obtained were subjected to an assessment of the effect of shooting parameters, i.e. shooting time, temperature and heating time, using the criteria: core-box fill rate, bending strength (RgU), apparent density and surface quality after hardening. The results of the trials on the use of sodium silicate moluding sands made it possible to further refine the conditions of next research into the improvement of inorganic warm-box / hot-box technology aimed at: reduction of heating temperature and shot time. It was found that the performance of the cores depends on the efficiency of the venting system, shooting time, filling level of a shooting chamber and grains of the silica matrix used.

Selection of Protective Coatings of Moulds for Castings of High-Manganese Cast Steel in Dependence of the Applied Moulding Sand Kind

2013 ◽  
Vol 58 (3) ◽  
pp. 853-857
Author(s):  
M. Holtzer ◽  
A. Bobrowski ◽  
D. Drożyński ◽  
J. Mocek
Keyword(s):  
Protective Coatings ◽  
Cast Steel ◽  
Silica Sand ◽  
High Manganese ◽  
Casting Surface ◽  
Hard Materials ◽  
Cast Steels ◽  
High Silica ◽  
Selection Of

Abstract High-manganese cast steels are characterised by a high abrasion resistance under friction conditions with a simultaneous influence of pressure and impacts. This cast steel is especially suitable for castings of excavator’s scoops, track links, streetcars crossovers, parts of crushers and mills for braking up of hard materials [1-4]. In order to obtain high quality castings of high-manganese cast steels in moulds on the high-silica sand matrices it is necessary to apply protective coatings, which prevent a direct contact between metal and matrix (SiO2). Manganese after being poured into a mould can undergo a partial oxidation forming MnO, which reacts with silica. As a result low-melting manganese silicates are formed, which in a form of a tight layer adhere to the casting surface, significantly increasing a labour input related to cleaning. Three kinds of protective coatings were tested: zirconium, corundum and magnesite. As a base moulding sands on high-silica sand matrices with three kinds of resol resins were applied. The quality of the obtained casting surface was assessed in dependence of the protective coating and resin kind and also in dependence of the metallostatic pressure value.

scholarly journals Effect of Sand Wetting on Physically Hardened Moulding Sands Containing a Selected Inorganic Binder. Part 1

2016 ◽  
Vol 16 (1) ◽  
pp. 73-78
Author(s):  
M. Stachowicz ◽  
K. Granat ◽  
Ł. Pałyga
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Water Glass ◽  
Mechanical Parameters ◽  
Significant Positive Effect ◽  
Technological Parameters ◽  
Physical Methods ◽  
High Silica ◽  
Positive Effect

Abstract In the paper, an attempt was made to evaluate the effect of preliminary wetting of high-silica base during preparation of moulding sands containing a selected grade of sodium water-glass, designed for hardening by traditional drying or by electromagnetic microwaves at 2.45 GHz. In the research, some water was dosed during stirring the sandmix before adding 1.5 wt% of the binder that was unmodified sodium water-glass grade 137, characterised by high molar module within 3.2 to 3.4. Scope of the examinations included determining the effect of wetting the base on mechanical parameters like compression, bending and tensile strength, as well as on technological parameters like permeability, abrasion resistance and apparent density. The research revealed a significant positive effect of adding water to wet surfaces of high-silica base grains on mechanical properties and quality of moulding sands hardened by physical methods, in particular by microwave heating.

scholarly journals Possibilities of Reclamation Microwave-Hardened Molding Sands with Water Glass

2014 ◽  
Vol 59 (2) ◽  
pp. 757-760 ◽  
Author(s):  
M. Stachowicz ◽  
K. Granat
Keyword(s):  
Tensile Strength ◽  
Ambient Temperature ◽  
Water Glass ◽  
Thermal Loading ◽  
Bending Strength ◽  
Processing Parameters ◽  
Molding Sand ◽  
Waste Foundry Sand ◽  
High Silica ◽  
Successive Operation

Abstract The paper presents results of a research on identifying opportunities for effective reclamation of waste molding sand with water-glass, hardened by microwave heating. The molding sand applied in the tests was prepared with use of selected type 145 of sodium water-glass. The sand was sequentially processed by microwave hardening, cooling, thermal loading to 800°C, cooling to ambient temperature, crushing and mechanical reclamation. These stages create a closed processing loop. After each cycle, changes of tensile strength and bending strength were determined. Results of the study show that it is possible to activate surface of high-silica grains of waste foundry sand hardened with microwaves, provided that applied are appropriate processing parameters in successive operation cycles.

scholarly journals Justification of modernization of groundwater treatment station

2021 ◽  
Vol 263 ◽  
pp. 04049
Author(s):  
Zhanna Govorova ◽  
Olga Zubareva ◽  
Vasiliy Semenovykh ◽  
Ekaterina Muraveva ◽  
Olga Yankovskaya
Keyword(s):  
Drinking Water ◽  
Technical Condition ◽  
Silica Sand ◽  
Groundwater Treatment ◽  
Concrete Corrosion ◽  
High Silica ◽  
External Corrosion ◽  
Manganese Compounds ◽  
Iron And Manganese

The main contaminants of groundwater are iron and manganese compounds, increased hardness, which are removed at groundwater conditioning stations. The article reviews the existing station that was built according to a conventional design and uses the method of simplified aeration with the following filtration through high-silica sand. Assessment of the technical condition of the station showed that the elements of the building are limited to work The filters are in poor condition, some of the filters are out of service, there are concrete corrosion, destruction of finishing layers in filters’ building, internal and external corrosion of metallic pipelines and valves, which depend on he quality of transported water. Wear of the technological pipelines is over 80%. Analysis of the efficiency of the station showed that it operates at 50% capacity and at the same time does not provide standards for the hardness of drinking water. Water consumption for the station’s own needs is 1.5 times higher than it was designed. There are no processing and reusing facilities for flushing water. Results of the technical and technological inspection of the station showed that there is a need for immediate modernization of the station including the improvement of the groundwater purification technology and bringing he quality to the standards for drinking water.

scholarly journals Investigations of Protective Coatings for Castings of High-Manganese Cast Steels

2013 ◽  
Vol 13 (1) ◽  
pp. 39-44 ◽  
Author(s):  
M. Holtzer ◽  
A. Bobrowski ◽  
D. Drożyński ◽  
J. Mocek
Keyword(s):  
Surface Quality ◽  
Protective Coatings ◽  
Cast Steel ◽  
Small Degree ◽  
Silica Matrix ◽  
Silica Sand ◽  
Hadfield Steel ◽  
High Manganese ◽  
Free Silica ◽  
High Silica

Abstract When cast steel castings are made in moulding sands on matrices of high-silica sand, which has a low fire resistance the problem of the so-called chemical penetration is distinctly visible. Whereas this effect appears to a small degree only when moulding sand matrices are of chromite, zircon or olivine sands. Therefore in case of making castings of high-manganese cast steel (e.g. Hadfield steel) sands not containing free silica should be applied (e.g. olivine sand) or in case of a high-silica matrix protective coatings for moulds and cores should be used. Two protective coatings, magnesite alcoholic (marked as coating 1 and coating 2) originated from different producers and intended for moulds for castings of the Hadfield steel, were selected for investigations. Examinations of the basic properties were performed for these coatings: viscosity, thermal analysis, sedimentation properties, wear resistance. In order to estimate the effectiveness of protective coatings the experimental castings were prepared. When applying coating 1, the surface quality of the casting was worse and traces of interaction between the casting material (cast steel) and the coating were seen. When protective coating 2 was used none interactions were seen and the surface quality was better.

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