A mild conditions synthesis route to produce hydrosodalite from kaolinite, compatible with extrusion processing

The most important problem that humanity is expected to face in the coming century shall be environmental pollution. On one hand, the population of human beings are using natural resources rapidly, on the other hand, they are adding hundreds of pollutants in the form of metals, acids, bases and etc. Thus, they have created an abnormal situation which has resulted in an imbalance in the natural systems. As the industrialization improves, it creates pollution and also it creates jobs for the people. Especially in developed countries, for instance European countries and U.S.A. there are also many stringent restrictions for the environmental pollution, and there are many laws, political arrangements. Of course , a pollution free environment will require a high cost, often an expensive operation. However , it is much more costlier trying to undo the damage done. On the basis of concept tried to mention above human beings have studied on the subjects related with environmental pollution. They have established waste water treatment plants, many kinds of recycling and recovery plants, and etc. In this study , it has been tried to establish such an idea that a pollution free environment may be available if this technical process is used properly. So, the first goal of this study is to provide a concise statement of the requirements and opportunities for obtaining environmental benefits. The second objective will be to provide economical savings while providing the environmental benefits at the same time. To emphasize the great importance of above mentioned subjects the application of recycle technology for the sodium hydroxide (NaOH), which is named as caustic soda in industrial processes, realized by means of an evaporation plant is used. Caustic soda is used in textile industry for mercerizing process as it is used in many different processes. To give the cotton more strength and to obtain a smoother surface and an improved affinity the mercerizing is essential. After being finished the mercerizing operation, generally the process solution (containing caustic soda) is discharged to the environment,. e.g. , rivers, seas and sewage. In spite of the fact that this application is widely spread in use, it is forbidden in all developed countries to discharge the caustic soda solutions even at a 1% concentration since the caustic soda is highly basic (highly alkaline). For this reason it is very harmful for the environment. It is possible to extract the caustic soda from the caustic soda solutions before discharging it to the environment for preventing the harms of this material. The washing water containing NaOH will be concentrated by H 2 O evaporation and shall be recycled in the mercerizing system. The concentration may take place in a single or multiple – stage (double–stage) installation under vacuum or atmospheric pressure. The washing water to be concentrated is moved from the storage tank to the first evaporation stage and the thermal energy for evaporation operation is added by the steam. The vapor coming from the first evaporation stage is used for the next evaporation stage as the heating steam of this unit. The vapor from the last stage is condensed in a condenser. The condensed vapor can be safely discharged and the concentrated caustic soda can be reused for the subsequent mercerizing operation. So, both economical profits and environmental benefits can be provided by reusing the caustic soda for next processes , after it is recovered by the help of this way. Desalination unit in Jeddah which is the capital city of Saudi Arabia , is an example for this kind of operations.. This plant was established 1970’s and has been used as both a power station and a desalination unit. At this plant the exhaust steam coming from the steam turbines is used as the heating steam for evaporators of desalination unit. Unfortunately, in our country, even in İzmir, the waste water of textile industry is discharged to the environment. Because , the environmental laws are not adequate and the enterprisers think that a recycling plant is not an economical investment. However , it is stated in this study that such a concept is not right. It has been tried to show that such an investment, i.e., “An Evaporation Plant for Recycling of Caustic Soda” may be profitable if it is installed and operated properly, and also it has been tried to increase the attractivity of these kinds of plants . It is hoped that, the laws and stringent restrictions related with environment shall be arranged, so that we shall live in a healthy world.

Removal and Recovery of Phosphonate Antiscalants

Experimental investigation and numerical simulation of plastic flow behavior during forward-backward-radial extrusion process

Nitrocellulose is a cellulose derivative that has many potential applications. Nitrocellulose can bemade through nitration reactions by reacting cellulose and nitric acid at low temperatures. Cellulose can be obtained from lignocellulose biomass such as palm oil empty fruit bunches (POEFBs). In this study, techno-economic evaluation of nitrocellulose production from POEFBs was investigated with various types of alkaline and acid pretreatments. Pretreatment of POEFBs with alkaline and acid was used to purify cellulose fraction as raw material for nitrocellulose. The combination process of POEFBs pretreatment with alkaline and acid can be classified into 4 process routes such as ammonium hydroxide and sulfuric acid pretreatment (Route-1), ammonium hydroxide and acetic acid pretreatment (Route-2), sodium hydroxide and sulfuric acid pretreatment (Route-3), and sodium hydroxide and acetic acid pretreatment (Route-4). The results showed that ammonium hydroxide and sulfuric acid pretreatment (Route-1) was the most profitable route to produce nitrocellulose. Economic parameter values such as return of investment (ROI), payback period (PBP), net present value (NPV) and internal rate of return (IRR) from ammonium hydroxide and sulfuric acid pretreatment (Route-1) were 11.49%, 5.85 years, US$ 442,427 and 13.35%.

In recent years, several studies with focus on developing state-of-the-art manufacturing technologies have been conducted to produce light vehicles by employing parts made of light materials such as aluminum and magnesium. Of such materials, magnesium has been found to pose numerous issues, because it cannot be deformed (plastic deformation) easily at low temperatures. Furthermore, oxidation on the surface of manganese occurs at high temperatures. This study analyzes the extrusion process for manufacturing magnesium bumper back beams used in vehicles, using finite element (FE) analysis. The properties of magnesium were determined through a compression test performed at high temperatures. And the temperature at which oxidation occurs at its surface was evaluated via an extrusion test. FE analysis was used to evaluate the extrusion load and temperature during the extrusion process, according to changes in initial material temperature and ram speed. Extrusion limit diagram of the extrusion process was derived based on the results of the FE analysis. Process conditions required to be established during the extrusion process were determined by using the derived extrusion limit diagram. The conditions were further validated by the extrusion test.

To study the molecular mechanism of protein interactions during extrusion processing, the changes in molecular weight distribution and quantity of soluble proteins in wheat extrudates as affected by extrusion temperature were investigated. Wheat flour was extruded at die temperatures of 160, 170, and 185 °C. After extrusion, the solubility of wheat proteins decreased dramatically in all tested solvents [water, 0.01 M sodium hydroxide, 0.5 M sodium chloride, 70% ethanol, 0.1 M hydrochloric acid, 0.05 M sodium phosphate buffer (pH 7.0 and 8.0), 6 M urea, 1% SDS, 2% mercaptoethanol] except for an aqueous solvent containing 1% SDS and 2% 2-mercaptoethanol, in which they were almost completely soluble. In the soluble-protein fractions of the extrudates, the content of disulfide bonds decreased dramatically and the content of sulfhydryl groups varied slightly. Both aggregation and fragmentation of wheat proteins occurred during extrusion processing as indicated by SDS−PAGE analysis. The synergistic effect betwe...

Modeling texture and microstructural evolution in the equal channel angular extrusion process

Development of numerical simulation methods and analysis of extrusion processes of particle-filled plastic materials subject to slip at the wall

Based on the results of isothermal compression test of IN690 super alloy for constitutive relationship and ring compression test for interface friction factor, a finite element model for Ni-based super alloy IN690 tube during hot extrusion process is established by using DEFORM-2D. High temperature, high speed and high load are considered in the model. Extrusion load in steady process for the typical size is in good agreement with the measured result. The extrusion load, billet temperature field, stress field, strain field and the strain rate field during deformation process are obtained. Simulation results show that extrusion process can be divided by upsetting, filling, steady-state extrusion and end-stage extrusion. Little change of temperature occurs in upsetting and filling stages extrusion. The maximum temperature increase of billet appears at peak load and stable value 50°C is obtained in steady-state extrusion. Temperature decrease of billet rises up as extrusion process goes on. The maximum of equivalent strain appears at peak load. The maximum equivalent stress increases rapidly to a peak value in initial stage, and rises up slowly in steady-state extrusion process. Equivalent strain and equivalent strain rate keep unchanged in steady-state extrusion.

The integration of desalination plants and mineral production

Stability and physical properties of alkylsilane and alkylphosphonate self-assembled monolayer (SAM) films on metal oxide substrates characterized at the micro- and nanoscale

Low energy desalination and wind energy — sustainable solutions for drinking water production

Remineralization of Reverse Osmosis (RO)-desalted water for a Moroccan desalination plant: optimization and cost evaluation of the lime saturator post

To report our experience using low temperature and energy in the modification of the slow pathway in pediatric patients with atrioventricular nodal reentrant tachycardia. A concern in performing a slow pathway modification is the possible damage of the normal AV conduction system. Lesion size has been shown to have a linear relationship with temperature. Previous reports have used energy of 25-50 W that generate temperatures of 60 degrees C -70 degrees C for successful procedures. Report of results of attempted AV nodal slow pathway modification in 17 consecutive pediatric patients < 15 years of age at The Children's Hospital of Philadelphia from April 1995 to November 1997 using low temperature and energy. There were 18 successful slow pathway modifications with 1 recurrence in 17 patients. The maximum energy used during successful lesions was 32.7 +/- 13.8 W (range 15-50 W) with a mean energy of 26.4 +/- 13.3 W (range 12-48 W). The peak temperature during these lesions was 55.1 degrees C +/- 4.1 degrees C (range 48 degrees C-64 degrees C) with a mean temperature of 47.9 degrees C +/- 2.7 degrees C (range 44 C-540C). The mean number of radiofrequency lesions required for a successful modification was 5.8 +/- 6.7 (median 4.0, range 1-26). Patients have been followed for 2.08 +/- 0.79 years. Slow pathway modification can be performed successfully with a low incidence of recurrence in the pediatric patient using low energy and temperature. It is possible that this may lead to smaller lesions.

The paper presents the results of pilot batch production of cryolite using sodium chloride and sodium hydroxide by hydrochemical method, physical and chemical studies of the obtained products, as well as their testing in aluminium electrolysers with measurements of technological parameters before and after use. The conducted studies have shown that the process of production of a pilot batch of cryolite by hydrochemical method from hydrofluoric acid using aluminium hydroxide, sodium chloride and sodium hydroxide solutions proceeds at a temperature of 25 °C for 30-45 min. In this case, the yield of cryolite according to the first embodiment using sodium chloride is more than 80 %, since during the reaction a side hydrochloric acid is formed, which dissolves more than 15 % of the cryolite. When sodium hydroxide is used, the process proceeds similarly to the first variant with an increase in cryolite yield of more than 90%. According to pilot tests, the first variant produced 600 kg of cryolite and the second variant produced 620 kg of cryolite. The reliability of the process of cryolite production with the use of sodium chloride and hydroxide was confirmed by chemical and X-ray phase analyses using the modernised Dron-2 unit. It was found that the analysed samples correspond to the reference cryolite, indicating the interaction of sodium chloride and sodium hydroxide with fluoroaluminium acid. Also the obtained synthetic products have successfully passed pilot tests in aluminium electrolysers of JSC "TALCO" with control of technological parameters. On the basis of conducted researches the basic technological scheme of cryolite production by hydrochemical method with application of hydrofluoric acid, aluminium hydroxide, sodium chloride and hydroxide was developed. As a result of the research it was found out that the technology of cryolite production with the use of sodium chloride and hydroxide is easy to implement and cost-effective due to low energy consumption of production and the use of local mineral raw materials.