Addition Of Sodium Carbonate Research Articles

Surfactant assisted synthesis of precipitated calcium carbonate nanoparticles using dolomite: Effect of pH on morphology and particle size

Synthesis of nanomaterials from readily available minerals for industrial applications is a growing research area. Understanding the causes of their properties becomes handy in utilization. In this study, an effective sucrose solution based method was employed for the extraction of calcium from dolomite to synthesize precipitated calcium carbonate nanostructures with different morphologies and sizes. It was found that 30% (w/v) sucrose solution extracted approximately 91% of calcium from dolomite forming a calcium-sucrate complex. Carbonation was achieved by CO2 bubbling and aqueous sodium carbonate addition. Precipitation was performed under different pH values of 7.5, 10.5 and 12.5 in the absence of an anionic surfactant and in the template of sodium dodecyl sulfate (SDS)/calcium-sucrate at pH 12.5. It was found that CO2 bubbling slightly promotes smaller particles. The anionic surfactant enables particle size and agglomeration reduction while introducing some hydrophobicity. The smallest particles were achieved at a range of 40–55 nm in the presence of SDS/sucrose template and were of spherical morphology. By changing the pH, a tendency to form different polymorphs and shapes of calcium carbonate was observed.

Effect of Sodium Carbonate on the Reduction Process of Nickel Slag from Sulawesi

Nickel slag is one of the results of the nickel ore smelting process which is still a waste and has not been used optimally. Considering the amount of nickel slag waste in Indonesia, the effort to utilize it into a more valuable product becomes very important. Therefore, in order to extract the precious metal content in nickel slag, this study aims to analyze the effect of adding sodium carbonate in the reduction process of nickel slag. In this study, the reduction process is carried out using coal as a reducing agent, where the variation of the reduction temperature is 800, 900, and 1000°C; while the variation of the ratio between nickel slag and additives is 1:1, 1:2, and 2:1. The XRD analysis results show that the temperature rise up to 1000 °C and the addition of sodium carbonate will increase the amount of sodium magnesiosilicate up to 29.4% and also hematite up to 25.1%. The same thing happened in samples with a ratio of 1:1 and 1:2 where the amount of sodium magnesiosilicate increased from 29.4% to 30.0% and hematite from 25.1% to 28.8%.

Rapid Nucleation of Reduced Graphene Oxide-Supported Palladium Electrocatalysts for Methanol Oxidation Reaction.

Small sized electrocatalysts, which can be obtained by rapid nucleation and high supersaturation are imperative for outstanding methanol oxidation reaction (MOR). Conventional microwave synthesis processes of electrocatalysts include ultrasonication, stirring, pH adjustment, and microwave irradiation of the precursor mixture. Ethylene glycol (EG), which serves as a reductant and solvent was added during the ultrasonication or stirring stage. However, this step and pH adjustment resulted in unintended multi-stage gradual nucleation. In this study, the microwave reduction approach was used to induce rapid nucleation and high supersaturation in order to fabricate small-sized reduced graphene oxide-supported palladium (Pd/rGO) electrocatalysts via the delayed addition of EG, elimination of the pH adjustment step, addition of sodium carbonate (Na₂CO₃), prior microwave irradiation of the EG mixed with Na₂CO₃, and addition of room temperature precursor mixture. Besides its role as a second reducing agent, the addition of Na₂CO₃ was primarily intended to generate an alkaline condition, which is essential for the high-performance of electrocatalysts. Moreover, the microwave irradiation of the EG and Na₂CO₃ mixture generated highly reactive free radicals that facilitate rapid nucleation. Meanwhile, the room temperature precursor mixture increased supersaturation. Results showed improved electrochemically active surface area (78.97 m² g-1, 23.79% larger), MOR (434.49 mA mg-1, 37.96% higher) and stability.

Synergy between sodium carbonate and sodium titanate nanotubes in the transesterification of soybean oil with methanol

Abstract Sodium titanate nanotubes (STN) modified by the addition of sodium carbonate (3–10 wt. %) were tested as catalysts for the transesterification of soybean oil with methanol giving good results. Prepared catalysts were characterized by N2 physisorption, X-ray diffraction, FT-IR, temperature-programmed desorption of CO2, scanning and transmission electron microscopy. The STN catalysts modified with sodium carbonate were significantly more active in the transesterification reaction than the reference catalyst containing 5 wt. % of Na2CO3 on alumina. The most active catalyst, STN with 10 wt. % of Na2CO3, resulted in the 97% yield of methyl esters at a short reaction time (30 min) in mild conditions (80 °C). High activity of the prepared catalysts was attributed to a synergetic effect between the support and the deposited sodium carbonate leading to a noticeable increase in the amount of strong basic sites able to generate methoxide anions required for the transformation of triglycerides to methyl esters. According to the FT-IR characterization, the above synergy was attributed to the presence of different types of carbonate species in the alumina and STN-supported catalysts. Upon reutilization, Na2CO3-containing STN catalysts showed a decrease in their activity due to leaching of the active phase in the reaction media.

Extraction of Molybdenum from Spent HDS Catalyst by Two-Stage Roasting Followed by Water Leaching

The petroleum refining industry produces a large amount of spent hydrodesulphurization (HDS) catalyst every year, representing a hazardous solid waste but also an important secondary resource. In the work presented herein, extraction of molybdenum from spent HDS catalyst by two-stage roasting followed by water leaching was investigated. The effects of sodium carbonate roasting and water leaching on the extraction of molybdenum as well as the effect of roasting on the molybdenum loss were investigated. The spent catalyst could be oxidized by blank roasting at 650°C for 2 h with molybdenum loss of 5.9%. Under the optimized conditions of sodium carbonate roasting (blank roasted spent HDS catalyst with 20 wt.% sodium carbonate addition at 650°C for 2.5 h) followed by water leaching (at 100°C for 2.5 h at liquid/solid ratio of 7 mL/g), the molybdenum leaching reached 94.0%.

Effect of sodium carbonate on the rehydration of milk protein isolate powder

Milk protein isolate (MPI) powder has poor rehydration ability. An alkaline pH environment has the potential to alter and improve its rehydration behaviour. Sodium carbonate, an approved food additive, is an alkaline reagent and consequently has some potential for improving the rehydration behaviour of MPI powder. The addition of sodium carbonate in this study was adjusted between 0 and 1 g/100 mL concentrations in water. The results showed that wettability worsened with higher sodium carbonate concentrations, due to strong films developing at the powder/water interfaces which inhibited water penetration into the bulk. However, appropriate agitation could effectively wet and disperse the powder. On the other hand, particle size and centrifugal sedimentation studies showed that increasing the sodium carbonate concentration greatly improved the dissolution ability of the MPI powder. The best dissolution occurred in 0.5 g/100 mL sodium carbonate solution, while some large undesirable aggregates occurred at 1 g/100 mL addition. The improved dissolution is most likely due to the higher pH increasing negative electrostatic repulsion and decreasing hydrophobic group attractions on casein micelle surfaces.

Thermal characteristics of ferronickel slag on roasting process with addition of sodium carbonate (Na2CO3)

Thermal characterization of ferronickel slag waste has been studied using TG / DTA, XRD, and SEM-EDX. The characterization of the initial samples of ferronickel slag was carried out TG / DTA to 1200°C. The result obtained is at a temperature of 800°C, there is an increasing mass and up to 4.68% at a temperature of 1200°C. At temperature of 807.4°C to 845.8°C, an exothermic reaction occurs. The increasing mass is due to the ferronickel slag which is originally in the form of metal, and then it was roasted to undergo an oxidation reaction so that the metal that has been formed, it returned into oxides. So that the weight of the sample mass increase. Samples of ferronickel slag added with sodium carbonate were also analyzed using TG / DTA. The results obtained are 2 endothermic peaks at temperatures of 90.6°C and 858.9°C with a total mass reduction of 49.3%. At a temperature of 90.6°C, there is a heavy loss caused by 2.38% loss of surface water. The XRD result of ferronickel slag is composed of enstatite (MgSiO3), forsterite (Mg2SiO4), fayalite (Fe2SiO4), and quartz (SiO2) structures. From the XRD analysis, the composition of silica oxide associates with magnesium and iron in the form of enstatite, forsterite, and fayalites is a very dominant composition. The roasting process of a mixture of ferronickel slag with sodium carbonate was carried out by heating at a temperature of 800-1000°C for 1 hour, and the sample result of roasting were analyzed using XRD. The result of roasting shows that the roasting process takes place more perfectly at higher temperature; it is indicated by the increasing phase intensity of SiO2 and the formation of sodium silicate (Na2SiO3). The result of SEM shows that the higher the temperature, the distribution of Na, Si, and O elements tend to cluster in the same place or spot, while the elements of Mg, Si, and O are less bonded.

Promotive Effect of Bicarbonate Ion on Two-Electron Water Oxidation to Form H2 O2 Catalyzed by Aluminum Porphyrins.

Two-electron water oxidation initiated by one-electron oxidation of aluminum porphyrins (AlTMPyP) is an alternative water oxidation to the conventional four-electron pathway and could help to avoid the bottleneck subject of photon-flux density in artificial photosynthesis. Here, a dramatic enhancement of the reactivity by bicarbonate ion in the two-electron water oxidation to form H2 O2 is reported. An addition of sodium carbonate (Na2 CO3 ) controlled both catalytic current and product selectivity of the two-electron water oxidation to enhance the activity of AlTMPyP at pH≈10-11. Controlled potential electrolysis experiments at different concentrations of Na2 CO3 (10-100 mm) showed that peroxide selectivity was improved up to approximately 73 % by the increase of [Na2 CO3 ] added to the system. The promotion of the reaction cycle was induced by an enhanced dynamic capturing of H2 O2 from the hydroperoxy complex of AlTMPyP through an attack of a bicarbonate ion. The detailed electrochemical studies and product selectivity indicated that the bicarbonate ion served as a good cofactor for producing H2 O2 from water. At stronger alkaline conditions (pH 12.5), however, a retardative effect of the addition of Na2 CO3 on the catalytic reactivity was observed.

In situ modification provided by a novel wet pyrolysis system to enhance surface properties of biochar for lead immobilization

Surface modification of biochar is significant to obtain more functionalized material for contaminants immobilization. In situ modification, modifying the biochar while the conversion process, was applied by a novel wet pyrolysis system. By using phosphoric acid as working medium, liquid/air interface was created to introduce low content of oxygen, under the control of appropriately settled reaction temperature. Followed with the addition of sodium carbonate to neutralize the system and increase mineral species, effective biochar adsorbent attached with large quantity of acidic oxygenic and phosphoric groups, and carbonate anions was finally produced. The biochar showed excellent decontamination performance of lead with a high adsorption capacity of 316 mg·g−1 and removal efficiency larger than 95%. The alteration of the characteristics after the adsorption confirmed the adsorption mechanism is the bi-function of surface coordination and precipitation. This novel route is easy handling and energy saving, promising it to be a reliable way to produce biochars with attractive surface properties for environmental decontamination.

Zinc Ferrite Decomposition by Sodium Carbonate and Calcium Oxide at Roasting of Steelmaking Dust

When re-melting scrap in electric arc furnaces (EAF), dust is formed. This dust is a rich zinc-containing raw material. The composition of the EAF-dust from JSC “Pervouralsk New Pipe Plant” was investigated. Dust contains 18 wt.% of zinc, more than 1/3 of zinc is a part of the slightly soluble in acids and alkalis of zinc ferrite ZnFe2O4. The aim of the work is to study the effect of roasting temperatures of 700, 850 and 1000 °C and the effect of CaO and Na2CO3 additives on the decomposition of zinc ferrite. Thermodynamic analysis of chemical transformations in dust during roasting showed that the additions of CaO and Na2CO3 provide destruction of zinc ferrite and promote the transfer of zinc into the acid-soluble form of ZnO. The effect of the roasting temperature, the duration of roasting and the amount of calcium oxide and sodium carbonate additions on the degree of zinc transition into acid-soluble form was studied experimentally. The best results were obtained at 1000 oС. The increase in the roasting time in the interval from 1 to 3 hours promotes an increase in the concentration of acid-soluble zinc in the cinder. The combined additions of 36 wt.% of Na2CO3 and 19 wt.% of CaO above the dust mass are optimal. The proportion of acid-soluble zinc in the cinder increased to 97–99 %, as a result of roasting under optimal conditions.

Characteristics of Activated Carbon from Oil Palm Fronds with the Addition of Sodium Carbonate (Na2CO3) and Sodium Chloride (NaCl) as an Activator

This paper aims to understand the difference in characteristics of activated carbon produced from oil palm fronds (Elaeis guineensis Jacq) through the addition of two different activators, namely sodium carbonate (Na2CO3) and sodium chloride (NaCl). To do this, activator concentration of 10 percent each with activation temperature of 600 oC were applied in the experiment. Moreover, to determine the quality of activated carbon produced, a morphological analysis of activated carbon surfaces as well as FTIR spectra analysis on activated carbon. Identification using FTIR spectrophotometer revealed that the activated carbon in this study contained functional groups of O-H, C = O, C = C, C-C, and C-H.

Viscoelastic Behavior of Alkyl Ether Sulfate Systems Containing Nanosized Colloidal Silica

AbstractSurfactant systems incorporating wormlike micelles (WLM) are utilized in both industrial and consumer products. While the viscoelastic behavior of such systems provides for many desired end‐use properties, there is often a need to further modify the rheological properties of such systems. These WLM systems behave much like polymer systems. Furthermore, incorporation of nanosized particles results in interaction of nanoparticles with the large WLM structures altering the rheological behavior. While there are a number of studies that have focused on the effect of particles on the rheological behavior in cationic surfactant systems, fewer studies have been done on systems containing anionic surfactants. In this study, relaxation behaviors in systems containing sodium alkyl ether sulfate and sodium carbonate were studied. The anionic surfactant was an alkyl ether sulfate with an average chain length of 12 carbons and one ethoxy group. WLM behavior was achieved through the addition of sodium carbonate. Ludox TMA, a nanosized colloidal silica, was employed at different concentrations in the WLM systems. Temperature was varied between 5 and 45°C. While characterization of relaxation in terms of the Maxwell model adequately described data below the threshold of ωτ ~1, the model failed to adequately describe behavior at higher frequencies. A modified expression with an additional relaxation mode adequately described relaxation throughout the frequency range studied. It was also found that zero‐shear viscosities generally increased with an increase in silica concentration, and relaxation times decreased. Measurements of relaxation due to a compressive stress via ultrasonic attenuation measurements in the surfactant/particle systems are also discussed.

Evaluation of Terpolymer-Gel Systems Crosslinked by Polyethylenimine for Conformance Improvement in High-Temperature Reservoirs

SummaryA terpolymer-gel system using low toxic polyethylenimine (PEI) as the crosslinker was developed for conformance improvement in high-temperature reservoirs. Suitable gelation time (GT), gel strength, and thermal stability could be obtained by selecting PEI molecular weight and adjusting terpolymer concentrations. With the increase of terpolymer concentration, GT decreases and the gel strength increases. However, in this research, the effect of PEI concentration on the gelation performance was much less obvious than that of the polymer concentration. Very low concentrations of sodium chloride (NaCl) can slightly shorten the GT. After critical concentrations were reached, the authors determined that the ions will delay the crosslinking reaction. Moreover, the addition of sodium carbonate (Na2CO3) can also lengthen GT. The gel systems were able to maintain thermal stability at 150°C. Uniformly distributed 3D network microstructures and the small size of the gel-grid pores made the network structure maintain thermal stability. The use of the terpolymer-gel-system gelation mechanism crosslinked by PEI can help petroleum engineers better understand and apply this terpolymer-gel system.

METHODS FOR COPPER EXTRACTION FROM PRECIPITATE AND USING OXIME MIXED WITH SODIUM CARBONATE

The paper covers experimental and theoretical studies of technical solutions for copper liquid extraction by organic extractants from sulfuric acid solutions that neutralize the negative effect of hydrogen ions released as a result of copper cations interaction with oximes on the copper extraction into the organic phase, and increase the technical and economic parameters of the process. In order to reduce the volume of processed solutions, copper extraction by the extractant solution in a diluent from the previously obtained thickened copper precipitate by sodium carbonate addition was studied. Subsequent operations for copper organic phase purification from metal impurities and re-extraction were carried out by methods known in liquid extraction. It was experimentally found that the use of copper pre-concentration in the precipitate makes it possible to increase the copper content in the extractant by 3—4 times to 1 g per 1 % (abs.) of the oxime content in the organic phase. It is required to maintain a ratio of 2 moles of oxime to 1 mole of copper in the precipitate to ensure rapid delamination and full extraction of copper. Dependencies of parameters were calculated for the stages of copper extraction from the thickened solution precipitate and extract washing. It was shown that extraction system parameters can be increased by using copper from the extractant emulsion solution obtained by mixing the oxime solution in a diluent and the aqueous solution of sodium carbonate. Based on the results of experiments, extractant emulsion with sodium carbonate added into the first stage of the extraction process makes it possible to significantly increase the copper distribution coefficient and saturate the extractant in terms of copper as much as possible. Maximum copper extraction from the solution is achieved at a molar ratio of carbonate and oxime in the emulsion equal to 1 : 2. The proposed technical solutions increase distribution coefficients and maximize the extractant working capacity during copper extraction. The lower volume of phases involved in extraction results in a substantially reduced number of extraction equipment and costs of raffinate purification from extractant and diluent destruction products. The proposed extraction methods can be used to extract copper from natural and technological sulfuric acid solutions, for example from mine waters and solutions generated when processing mineral raw materials and man-made waste.

Influence of the purification of bentonite clay from new deposits in the state of Paraíba-Brazil for use in water-based drilling fluids

Abstract Bentonite clay is used all around the world as an additive in drilling fluids. However, impurities present in this material can compromise the compatibility of the clay-fluid system. The present study aimed to analyze the effects of the purification of bentonite samples from new deposits in the state of Paraíba, Brazil, in order to make them usable in water-based drilling fluids. The samples were first purified by centrifugation, and their characteristics were determined using the following techniques: laser granulometry, X-ray diffraction, chemical analysis, cation exchange capacity, thermogravimetric analysis, and differential thermal analysis. After these determinations, the polycationic clay samples were made sodic through the addition of sodium carbonate (Na2CO3) in the proportion of 125 meq/100 g of dry clay. The rheological and filtration properties (apparent viscosity, plastic viscosity, and filtrate volume) were then tested. The results showed that the purification process was efficient for removing accessory minerals such as quartz, iron, and carbonates. With regard to rheological and filtration properties, the results following centrifugation showed that the material can be suitable for use in water-based drilling fluids.

Co-extraction of tungsten and molybdenum from refractory scheelite–powellite blend concentrates by roasting with Na2CO3 and SiO2 and leaching with water

ABSTRACTStudies on the recovery of tungsten and molybdenum from refractory scheelite–powellite blend concentrates – mainly composed of scheelite, powellite, and fluorite – were performed using soda-silicon roasting and water leaching processes. However, significant amounts of scheelite and powellite ore are present in an intergrowth state and the application of mineral dressing is not suitable for the separation and extraction of tungsten and molybdenum from this refractory ore. The effects of roasting parameters including sodium carbonate addition, roasting temperature, roasting time, and mass ratio of SiO2/concentrate (wSiO2/wconc.) and the effects of leaching parameters including leaching temperature, leaching time, and liquid-to-solid ratio on the leaching efficiency of tungsten and molybdenum were investigated. The results demonstrated the efficiency of this process for the extraction of tungsten and molybdenum from the ore. Under the optimum experimental conditions where soda-silicon roasting is performed for 2 h at 850°C with three times, the stoichiometric ratio of Na2CO3 (Na2CO3:WO3 and Na2CO3:MoO3) and wSiO2/wconc of 12%, and water leaching is subsequently performed for 1 h at 70°C with a liquid-to-solid ratio of 3:1, the leaching ratios of W and Mo are 98.89% and 99.41%, respectively.

Flotation separation of scheelite from calcite using carboxyl methyl cellulose as depressant

The effect of carboxyl methyl cellulose (CMC) on the flotation separation of scheelite from calcite using sodium oleate as collector was studied in this work. The results of flotation tests indicated that CMC could selectively depress the flotation of calcite. However, the addition of calcite strongly strengthened the depressing effect of CMC on scheelite flotation. The addition of sodium carbonate could eliminate the adverse impact of calcite on the performance of CMC in scheelite flotation, and a concentrate with both high grade of WO3 and scheelite recovery could be achieved under CMC in the presence of sodium carbonate. Zeta potential results indicated that CMC adsorbed more strongly on calcite surface than that on scheelite surface, and the addition of CMC prevented the adsorption of the sodium oleate on the calcite surface.

Effect of Sodium Carbonate Concentration in Calgon on Hydrometer Analysis Results

Calgon (a combination of sodium hexametaphosphate and sodium carbonate) has proved to be the most effective dispersing agent in determining the grain size distribution of fine-grained soils by means of the hydrometer analysis. Previous research on the effect of the sodium hexametaphosphate content of dispersing agents on the clay contents showed that the addition of sodium carbonate to sodium hexametaphosphate increases its dispersing effectiveness. Hence, Calgon 35:7 was used /recommended by many researchers/methods and proved to be the most effective dispersing agent. Although previous work focusing on the effect of varying the concentration of sodium hexametaphosphate in Calgon has been reported, the effect of the concentration of sodium carbonate in Calgon has not been assessed and reported. For this reason, in this investigation a series of hydrometer test analyses were conducted using the 152H and ASTM 152H: E100 hydrometers with Calgon in ratios of 35:0, 35:20 and 35:30. It was observed that with any increase in sodium carbonate content beyond 7 grams, the percentage clay content actually decreased tremendously in the case of hydrometer 152H. However, for the other hydrometer, Calgon (35:0) proved to be most effective combination. Thus, the increase in the sodium carbonate content in Calgon, beyond 7 g/ litre, is not recommended.

A method for recovery of iron, titanium, and vanadium from vanadium-bearing titanomagnetite

An innovative method for recovering valuable elements from vanadium-bearing titanomagnetite is proposed. This method involves two procedures: low-temperature roasting of vanadium-bearing titanomagnetite and water leaching of roasting slag. During the roasting process, the reduction of iron oxides to metallic iron, the sodium oxidation of vanadium oxides to water-soluble sodium vanadate, and the smelting separation of metallic iron and slag were accomplished simultaneously. Optimal roasting conditions for iron/slag separation were achieved with a mixture thickness of 42.5 mm, a roasting temperature of 1200°C, a residence time of 2 h, a molar ratio of C/O of 1.7, and a sodium carbonate addition of 70wt%, as well as with the use of anthracite as a reductant. Under the optimal conditions, 93.67% iron from the raw ore was recovered in the form of iron nugget with 95.44% iron grade. After a water leaching process, 85.61% of the vanadium from the roasting slag was leached, confirming the sodium oxidation of most of the vanadium oxides to water-soluble sodium vanadate during the roasting process. The total recoveries of iron, vanadium, and titanium were 93.67%, 72.68%, and 99.72%, respectively.

The effect of NaOH (natrium hydroxide) to slag nickel pyrometallurgy in different temperature and additive ratio

Nickel slag is one of the output from nickel ore smelting. In Indonesia itself, further utilization of valuable elements in it is needed to be processed. Nickel slag also has Fayalite (Fe2SiO4) content where nickel and copper are spread evenly on the iron matrix silica which then complicate the process of increasing nickel and copper content. The addition of Sodium Carbonate (Naoh) is used as a silica binder and as an alternative way to increase nickel and copper content. In this research, pyrometallurgy is done by coal as a reductor in 800°C, 900°C and 1000°C operating temperature and ratio between nickel slag and additive equal to 1:1, 1:2, and 2:1. Based on this study, it is obtained that with the increasing of temperature without additive, there is still found the presence of silica in a form of Fe-rich Forsterite (FeMgSiO4) and Olivine (NiMgSiO4). Whereas with the presence of additive in slag nickel pyrometallurgy with a different temperature and ratio, it is seen that there is a phase formation of Sdoium Magnesiosilicate (Na2MgSiO4), Magnesium Oxide (MgO) and Wustite (FeO) which proved the binding of silica and has liberate iron that helps the process of increasing nickel and copper content.