These impurities have to be eliminated because they will produce unwanted insoluble salts by reacting with alkali and carbon dioxide, thus affecting the quality of the soda ash. Brine purification is carried out when magnesium ions are precipitated as hydroxide with milk of lime (Ca(OH)2) whereas calcium ions are precipitated as carbonate with soda ash (Na2CO3). This process is known as lime-soda treatment. The chemical reactions are as follows: Mg2+ + Ca(OH)2 → Mg(OH)2 + Ca2+ Ca2+ + Na2CO3 → CaCO3 + 2Na+ 2. Limestone burning and lime slaking The limestone (CaCO3) used must contain low concentration of impurities.
The origin of sulphate ions in the soil solution is in some circumstances due to the presence of sulphur-rich minerals such as pyrite in the parent material. By weathering and oxidation, the sulphur in these minerals is transformed into sulphuric acid which in calcareous soils reacts with CaCO3 to form gypsum. On irrigated land, leaching of saline soils containing sulphate and calcium in the soil solution leads in some circumstances to the precipitation and accumulation of gypsum in the subsurface horizon. The formation of gypsum may result from replacement of NaCl by CaSO4 when the irrigation water contains a substantial amount of calcium and sulphate. But it could be also a result of a partial leaching of salts from the soil because NaCl is much more soluble than CaSO4.
In the third distillation tower (<20°C), styrene is distilled away from tars. The organic phase must be transported completely and non-stop into the distillation column under vacuum which works at 20m bar. The motor driven control valve is used to check the pressure difference which is adjusted automatically or by manual control inside the distillation column (Behr, 2005). Styrene can be polymerized easily, therefore inhibitor is added. In this case, 4-tert-butylcatechol (TBC) inhibitor is added by pump inside the third distillation tower.
STABILIZATION OF CLAYEY SOIL USING CHEMICALS Bhawna Sahay1, Prof. V.K.Arora2 ABSTRACT: Soil stabilization is a technique of enhancing the geotechnical properties and strength of soil to modify the bearing capacity and durability of weak soil. There are numerous methods of stabilising the soil such as soil replacement , grouting ,reinforcing ,chemical, mechanical, electrical method, using additives such as fly ash, rice husk, gypsum and cement. Chemical stabilization with lime and sodium hydroxide is time saving method. All these chemicals are highly reactive in nature and react with clay particles during stabilization process which leads to improve the geotechnical properties of soil. KEY WORDS: stabilization; optimum
Chapter 3 PREPARATION OF BIODIESEL 3.1. Preparation of Canola Methyl Ester Fig: 5 Preparation of Canola Oil Methyl Ester 3.2. Preparation of Aloevera Methyl Ester Fig: 6 Preparation of Aloevera Oil Methyl Ester 3.3. Pre-treatment Filtered Canola and Aloevera oils are first taken to remove moisture. As water content of the feedstock is critical parameter and should be kept below 0.06% w/w for better conversion of oil to esters.
STIMULATION OF PETROLEUM HYDROCARBON DEGRADATION IN SOIL GAYATHRI.M DATE OF SUBMISSION:19-12-2017. ABSTRACT: Hydrocarbon are mainly the pollutants from oil refineries and oil spills. These pollutants can be degraded by a consortium or cocktail of microorganisms e.g. pseudomonas, Corynebacterium, Arthobacter, Mycobacterium and nocardia. Biodegradation has at least three outcomes (1) a minor change in an organic molecule, leaving the main structure still intact;(2) Fragmentation of a complex organic molecule in such a way that the fragments could be reassembled to yield the original structure; and (3) complete mineralisation, which is transformation of organic molecules to inorganic forms.
Silica fume is a by-product resulting from the reduction of high-purity quartz with coal/coke in an electric arc furnace during the production of Silicon metal/Ferro-silicon alloys. The use of silica fume in concrete can achieve a lower permeability, which is good for the durability issues of bridge decks. However, it has a high hydration heat so that it has a higher tendency of plastic shrinkage cracking. Darwin et al. (2007) stated that when cast with a high-absorption coarse aggregate, the addition of silica fume results in a reduction in shrinkage at all ages.
The TLC plate can be any sheet of metal or plastic that is coated with a thin layer of solid adsorbent. Most often the thin layer used for TLC plate is either silica or alumina. TLC works by placing a chosen polarity of a reasonable volume of mobile phase in the TLC jar. A TLC plate contains the spot of the analysed/standard components near the bottom of it is placed in the jar. When the mobile phase rises up gradually to the top of the plate, the components spotted migrate along with the mobile phase until they get absorbed by the stationary phase.
This chapter includes a literature review of the structure of soils and their minerals, especially montmorillonite and kaolinite, they are the predominant clay minerals found in natural soil. In general the problems of expansive clay are also discussed together with natural soil stabilization. Special consideration is given to Sugarcane bagasse ash stabilization, including the general soil-Sugarcane bagasse ash reactions, effect of Sugarcane bagasse ash on compaction characteristics, plasticity, volume stability and strength. The changes which occur in clay soil when Sugarcane bagasse ash is added can be divided into two categories, modification and stabilization. During modification calcium ions are absorbed by clay particles in cation exchange reactions.
The Mixing of quicklime with water will release hot bubbles air. CaO + H2O (Water) —–> Ca (OH)2 (Slaked lime) + thermal Lime as a stabilizing agent typically used slaked lime or calcium hydroxide (Ca(OH)2). Because if using quicklime can endanger the test equipment (causing corrosion) and safety of workers, because quicklime is hot lime. D. Consolidation Consolidation is a process of shrinkage volume on perfectly saturated soil with low permeability due to the pore water drainage. In other words, consolidation is a wring out process of ground water due to the operation of the load, which occurs as a time function because of small permeability.