Soda Ash Production Research Articles

A new strategy for the comprehensive utilization of wastewater from the production of soda ash by sodium sulfate-based ammonia-soda process

The production of soda ash by the ammonia-soda process using carbon dioxide and ammonia for sodium sulfate is an effective method to realize the comprehensive utilization of waste resources of sodium sulfate, but this method produces a large amount of wastewater whose main substances are sodium bicarbonate and ammonium sulfate, which limits the modular industrial application of the production of soda ash by sodium sulfate-based ammonia-soda process(SSA-Process). At present, the main utilization method for the wastewater from the production of soda ash by SSA-Process is evaporation crystallization method to deal with the by-products of sodium sulfate and ammonium sulfate, which is a low-value, complex and energy-consuming process, so is an urgent need for a low-cost, high-value, short-process method to comprehensively utilize wastewater from the production of soda ash by SSA-Process. Based on the application theory of calcium hydroxide (Ca(OH)2) in the traditional ammonia-soda process, this present study systematically investigated the causticization law and mechanism of Ca(OH)2 in a simulated wastewater from the production of soda ash by SSA-Process. On this basis, a new process of Ca(OH)2 segmented causticization was developed to realize the comprehensive utilization of wastewater from production of soda ash by SSA-Process. The results showed that this process enabled a highly efficient ammonia cycle for cost reduction and the production of high purity ultrafine calcium carbonate products and sodium sulfate solids, as well as calcium-based raw material for building materials.

Wall-scaling prevention in cryogenic external cooler of ammonium chloride solution by liquid-solid fluidization

A double-tube cooler with liquid-solid circulating fluidization operation and corresponding parameter measuring system are developed to avoid fouling of inner walls of heat exchange tubes in a cryogenic temperature external cooler of ammonium chloride solution in soda ash production. Wall-scaling prevention performance of the cooling process is experimentally evaluated using convection and overall coefficients, enhancement factor, wall temperature and fouling resistance. Effects of different volume fractions of added particles, particle size, superficial liquid velocity, and cooling medium temperature on heat transfer are examined. Under present conditions, convection coefficient of liquid-solid flow inside the tube of external cooler is higher than that of the liquid phase flow, increased by 0.7–2.8 times, enhancing cooling performance obviously. Convection coefficient initially increases and then decreases as the volume fraction of added particles increases, reaching its maximum value at a volume fraction of 2.0%. The wall-scaling prevention effect of glass beads mainly depends on the volume fraction of added particles; optimal anti-fouling effects are achieved when adding particles at a volume fraction of 2.0%, regardless of changes in superficial liquid velocity or cooling medium temperature. This study lays a foundation for industrial applications of this new technique of fluidized bed external coolers.

Spatiotemporal lakes surface area changes over 35 years and potential causes in the Central Rift Valley, Ethiopia

Study RegionCentral Rift Valley (CRV) region, Ethiopia. Study FocusThe study aims to investigate the spatiotemporal change in lake water surface extents over 35 years (1986–2020) and identify potential causes. Three alternative multispectral water indices—Normalized Difference Water Index (NDWI), Automatic Water Extraction Index (AWEI), and Modified Normalized Difference Water Index (MNDWI)—derived from Landsat sensors (TM, ETM+, OLI) were utilized to extract and analyze the lake surface area. The Mann-Kendall correlation was applied to examine whether hydro-meteorological and anthropogenic variables are possible causes for changes. New Hydrological Insights for the RegionMNDWI outperforms other indices with over 96 % accuracy in mapping lake surface area. Lake Abiyata experienced the most significant reduction in surface area from 1986 to 2020 (>50 %), followed by Lake Ziway (<2 %) while Lake Langano remained relatively stable. This significant reduction positively correlates to alterations in lake water depth (R2=0.92). Factors such as increased temperature, evaporation, and water abstraction for soda ash production negatively correlated with lake surface area, while inflow from Bulbula River and mean annual rainfall showed positive correlations. Abiyata Lake's decrease in surface area is primarily attributed to water abstraction for soda-ash manufacturing and incoming river flow. If the current trends in water abstraction from the Lake and income water diversion continue, there is a high possibility that Lake Abiyata will change into a terminal lake shortly.

Nano-micron soda residue as green nucleation seeding additive for silicate cement

Soda residue (SR) is a kind of by-product by the ammonia-alkali process in the soda ash production, which contains calcium components, such as calcium sulfate and calcium chloride. In this work, the feasibility of using SR as an accelerating additive for Portland cement (PC) was investigated. Wet milling method was used to prepare nano-micron SR seed with D50 of 246 nm. A binary system of PC and SR seed was designed, and its compressive strength, hydration kinetics and microstructure were studied. Results showed that the 12-hour compressive strength of PC was greatly increased by 1.69 times when the dosage of SR seed was 6%. This improvement was attributed not only to the nucleation seeding and filling effect of the SR seed, but also to the presence of pre-dissolved chlorine and sulfate ions from SR particles. Furthermore, the pore volume was reduced by more than 16%, the critical pre radius was decreased by 86.3%, and the gel pore content was 2.3 times that of reference group, indicating a high microstructure refinement and gel binding contribution of SR seed.

Determination of Carbonate and Bicarbonate in Specific Samples of Trona Deposit

Trona is one of the natural forms of sodium carbonate minerals, it is well known as (sesquicarbonate) or (trona) and is known in Arabic as (natron) or (atrun). The possibility of determining some constituents of trona ore was studied, using the methods of purification, separation, titration gravimetric analysis and calcination. The aim of this study is to determine the major chemical Constitutes of three types of trona from different locations in Sudan, A chemical analysis has been carried out on these samples to determine their major constituents, and their quantities, using different analytical techniques. From the results obtained, it was found that the percentage of carbonate and bicarbonate for Northen, Westen, and Southern Darfour, were (35.52%: 18.19%), (25.87%: 12.20%) and (16.82%: 6.24%) respectively. These results suggest that the use of trona deposits for soda ash production is promising and important. We can recommend the use of trona as a source for the production of sodium carbonate.

Production of Granular Calcium Chloride From Waste Limestone Stone by Hydrochloric Acid Decomposition Method

In the JV LLC Kungrad Soda Plant of the Republic of Uzbekistan, after the lime slaking process in the limestone roasting and lime slaking shop for soda ash production, solid waste consisting of a certain amount of free calcium oxide and impurities contained in the feedstock and separated from lime milk is discharged into a sludge accumulator for solid waste. The volume and composition of discharged solid waste (stones from the inner part of the stone sieve pos. L0206, sand from the milk sieve pos. L0204 and stone sieve pos. L0206) per 1 ton of finished products is over 50 kg. Imports of granular calcium chloride to Uzbekistan amount to more than $6 million per year.

New Process for Na2CO3 Production from Na2SO4 Based on Modeling the Na2SO4-(NH4)2SO4-MEA-MEG-H2O System.

Alternative means for soda ash (Na2CO3) production from sodium sulfate (Na2SO4) are needed due to the intensive consumption of energy in the conventional Mirabilite-Solvay process (MSP). We demonstrate a new process to produce soda ash using sodium sulfate as a feed material. The new process relies on the antisolvent crystallization of unreacted Na2SO4 to separate it from soluble (NH4)2SO4 in a mixed monoethanolamine (MEA) and monoethylene glycol (MEG) solution. To develop the process, the solubilities of Na2SO4 and (NH4)2SO4 solids in aqueous mixed MEA-MEG solutions were first measured and then modeled using regressed paired-ion interactions from the electrolyte nonrandom two-liquid (E-NRTL) model. Anhydrous dense soda ash with a bulk density of up to 1146 kg/m3 was obtained when the concentrated Na2SO4 brines reacted with CO2 and NH3.

Method for Processing Distiller Liquid for Commercial Products

Soda ash is widely used in the glass, chemical, metallurgical, petroleum, textile, pulp and paper, food, paint and varnish industries, in the production of various salts, artificial fiber, in the leather industry, in the purification of water and brines. Currently, there are more than 75 soda enterprises in the world, producing 50-65 million tons of soda ash per year. Of the existing methods for producing soda ash, the most widespread (70%) is the ammonia method. Currently, distillation liquid is almost not processed and from the distillation station is first sent to storage tanks (the so-called white seas), and then discharged into water bodies, which leads to their pollution and salting. In the JV LLC Kungrad Soda Plant of the Republic of Uzbekistan, the distiller liquid after the distillation process in the ADCF (Absorption Distillation Carbonization Filtration) workshop of the I and II stages of soda ash production is discharged into a sludge storage tank for liquid waste. The volume of discharged distiller liquid is 9.08×10 m3per 1 ton of finished product (this amounts to 5448-5493.4 m3 per day, more than 1.8 million m3 per year).

Reduction of Carbon Monoxide Emissions into the Atmosphere When Burning Fuel Oil in Technological Thermal Power Plants

An effective method and device for additional heating of fuel oil used in the production of soda ash as fuel in soda drum dryers has been developed. It is concluded that the use of a high-frequency induction unit mounted on the fuel oil supply line in the thermal power equipment of soda ash drum dryers provides an increase in the temperature of fuel oil from 60 to 98 °С, a reduction in its specific consumption by 15.7 % and a reduction in carbon monoxide emissions into the atmosphere from 0.20 to 0.024 g /s.

Strength formation mechanism and curing system optimization of low-carbon cementitious materials prepared by synergistic activation of multiple alkaline solid wastes

Lack of proper disposal of carbide slag (CS), soda residue (SR), and red mud (RM), which are alkaline solid wastes released from the production of acetylene, soda ash, and alumina, respectively, adversely affects the environment. This study synthesized a new low-carbon cementitious material using CS-SR-RM-fly ash (FA) as raw material and optimized its curing method.The influence of raw material composition and various curing systems on the mechanical properties and microstructure of specimens was analyzed using compressive strength, chloride ion consolidation, XRD, FTIR, and SEM-EDS. The optimum ratio of CS:SR:RM:FA was determined to be 2:1:4:3, and the compressive strength of 3/28 d at room temperature (RT) sealed curing reached 10.7/22.1 MPa. The alkaline environment created by CS-SR-RM facilitated the decomposition of active components in FA and RM, contributing to the formation of a stable three-dimensional network comprising N-A-S-H gel, C-(A)-S-H gel, and Friedel's salt crystal product. High-temperature (HT) curing at 80 °C for 8 h significantly enhanced early strength, with strength growth rates of up to 147.7/29.9% compared with RT sealed curing at 3/28 d. HT curing promoted the rapid and steady growth of hydration products, resulting in increased structural compactness and improved strength. The present study offers suggestions for reducing the environmental pollution caused by alkaline solid waste and developing new resource utilization means.

The use of calcium peroxide CaO2 for wastewater treatment from chromium (VI)

The at meant of waste water from hexavalent chromium ions with calcium per oxide CaO2 was investigated. This product is obtained from soda ash production waste. Clarified part of still waste suspension (distillation suspension) contains calcium chloride and sodium chloride. The process of producing calcium peroxide is based on the interaction of calcium chloride with solutions of calcium peroxide and sodium hydroxide. A two-step (reagent) method of purification from hexavalent chromium is proposed. The first stage of the reagent method consists in reducing (conversion) toxic hexavalent chromium to a less dangerous trivalent chromium, and the second - in converting trivalent chromium to an insoluble state (into a hydroxide). The conversion (reduction) of Cr6+ to Cr3+ is carried out using calcium peroxide as a reagent. Reductionis carried out in an acidic medium, and to precipitate trivalent chromium in the form of chromium hydroxide (Cr(OH)3) waste water is neutralized using neutralizer Ca(OH)2. This method of wastewater treatment from hexavalent chromium can be effective in small and medium production, especially in the absence of general treatment facilities.

Sodium Hydroxide-Based CO2 Direct Air Capture for Soda Ash Production─Fundamentals for Process Engineering

This work introduces the principles and supplies the first key parameters for replacing the conventional ammonia-soda (Solvay) process with a new environmentally friendly and sustainable process. For this, the absorption of diluted CO2 (0.0153–1.2 vol %) in carbonated NaOH solutions was experimentally studied in a temperature range relevant for direct air capture (DAC) in the middle Europe (5–20 °C). A dynamic process model was formulated and solved based on the literature parameters. It was found that by refitting the parameters, the average error was reduced from 9.49 to 7.8%. The absorption performance was evaluated using the mass transfer coefficient (KG,CO2), which is considered as a useful parameter for the future process design. The mass transfer coefficient reaches a maximum amount of about 3 mm/s at around 6 wt % NaOH, 0 wt % Na2CO3, 20 °C, and 500 ppm CO2. The effects of NaOH and Na2CO3 concentrations and temperature on the mass transfer coefficient were experimentally and theoretically studied. Considering all effects simultaneously, the design aspects for an efficient NaOH-based CO2 DAC process for Na2CO3 production are concluded, in which KG,CO2 decreases with rising temperature while operating at saturated ion concentrations of Na2CO3.

NON-TRADITIONAL KARST TYPES IN THE SOUTHERN URALS AND CISURALS

Despite the wide distribution of sulfate and carbonate karst in the study area, the nontraditional, rarely encountered karst types are also registered. These are clastokarst, karst of calcareous tuffs, sulfide karst, salt karst and marble karst. For each of these nontraditional types of karst, the conditions and factors of development were determined according to the karstic rock composition. Calcareous tuff karst is the least common in the study area, meanwhile clastokarst is widespread. Calcareous tuff karst is spread in the westernmost part of the Southern CisUrals, in the eastern outskirts of the Volga-Ural anteclise; and clastokarst is found in the western margin of the Yuryuzan-Sylva depression of the CisUrals marginal foredeep. Sulfide karst is developed in the plains of the Southern TransUrals within the Magnitogorsk megazone of the Ural folded system, and salt karst occurs in the flat foothills of the Southern Urals within the Belaya Megadepression and the Shikhan-Ishimbai saddle of the CisUrals marginal foredeep. It has been established that the previously identified areas of clastokarst distribution in the west of the area under consideration are not confirmed by modern and Pleistocene forms of its manifestation. The negative impact of clastokarst on economic facilities and humans is comparable to the impact of the most common and dangerous sulfate karst, and this must be taken into account when designing and constructing new buildings and engineering structures. Salt karst is manifested in artificial leaching of rock salt at a depth, such salt is necessary for the production of soda ash (JSC “Soda”); the formed voids are used as underground storage facilities for oil products (OJSC Podzemneftegaz). Calcareous tuff karst is a rare type of karst in the region under consideration, it can be observed at the complex natural monument “Shumilovsky waterfall”. Surface manifestations of sulfide karst can be a search feature of new copper-sulfide deposits. Non-traditional types of karst have both positive and negative practical implications. Karst in marble complicates the development of mineral deposits, and clastokarst complicates the economic development of the territory. Calcareous tuff karst creates unique local landforms, and sulfide karst is of practical importance in the search for new mineral deposits. On the one hand, salt karst determines the extraction of minerals deposits and contributes to the creation of useful underground storage facilities, on the other hand, it destroys them.

Stability Analysis of Model-Free Adaptive Fuzzy Logic Control System Applied for Liquid Level Control in Soda Production.

Efficient control of liquid level - in a carbonization column (CCl) of soda ash production plants - is a difficult task because the plants are nonlinear, subjected to disturbances and lack a reliable mathematical model. To attain such efficient control, model-free fuzzy logic controllers (FLC) based on empirical knowledge are successfully developed and implemented, and adaptation mechanisms are added to aid the FLC tuning and compensate for plant changes. However, the stability analysis - of the adaptive FLC (AFLC) systems - is a critical issue that needs addressing. For this reason, the current investigation is devoted to the development of a method for analyzing AFLC system stability using robust stability and robust performance criteria. The suggested method is employed for the stability analysis of a designed PID AFLC utilized for liquid level control in an industrial CCl. The obtained results reveal that the AFLC preserves stability and high system performance in the whole range of adaptation and considered changes of the plant and the operation conditions. Moreover, the results unveil that the developed method can also be applied for the design of a robust FLC system that competes with adaptive counterparts.

Implementation of an integrated management system in calcium soda production

By amalgamating these essential pillars, the integrated management system endeavors to revolutionize the calcium soda production paradigm, ensuring harmonious coexistence between economic progress and ecological responsibility. This manuscript will explore the key components, challenges, and potential benefits of integrating such a system while shedding light on the transformative impact it can have on the industry as a whole. As we embark on this journey towards a more sustainable and efficient future, the implementation of an integrated management system emerges as a cornerstone in shaping the trajectory of calcium soda production and contributing to a greener and safer world. This article highlights the significance of integrating standards in the soda ash production process, focusing on improving product quality, ensuring competitiveness, and meeting high demand in domestic and foreign markets. It also explores the development and implementation of a quality management system (QMS) based on the ISO 9001:2015 standard. Additionally, the advantages and disadvantages of obtaining SMT certification for compliance with international ISO standards are discussed.

Solvay claims soda ash breakthrough

Solvay is piloting a soda ash production process that it claims will reduce CO 2 emissions by half and eliminate limestone in its effluent, which currently contributes to the release of heavy metals into the sea. The company has reached a settlement with the activist investor Bluebell Capital Partners that calls for it to roll out the new process across all of its soda ash plants by 2050. In parallel, Solvay will take shorter-term measures to reduce the amount of limestone released into the sea from its plant in Rosignano, Italy. Solvay is the world’s largest producer of soda ash (sodium carbonate), which is used to make glass and other products. Solvay’s process uses brine and limestone as raw materials and ammonia as a catalyst. The process creates large amounts of CO 2 from the burning of fossil fuels and generates powdery limestone, which contains traces of heavy metals. The

Solvay claims breakthrough in soda ash production

Solvay claims breakthrough in soda ash production

Changes in Synthetic Soda Ash Production and Its Consequences for the Environment

This publication presents a series of data of one of the most difficult chemical processes to implement in industrial conditions. Obtaining soda using the Solvay technique is a process with a world volume of about 28 Tg per year. The process is extremely physico-chemically complex and environmentally burdensome. The paper presents information on a multi-component system containing three phases with a chemical reaction. Calculations for such systems and their engineering are very complicated, but the authors show how the results of this work can be applied. This paper also describes modifications of the soda process to minimize the environmental burden and minimize the production input of Na2CO3. The modifications were beneficial in reducing CO2 emissions and increased the efficiency of the soda process, resulting in a measurable financial benefit. At the scale of the plant where the experiment was carried out, this reduction in CO2 emissions amounts to 7.93 Gg per year.

CARBON FOOTPRINT OF SODA ASH PRODUCTION

Greenhouse gases such as carbon dioxide, methane and others are believed to have a significant impact on global climate warming. Emissions of carbon-containing gases are commonly referred to as carbon footprint which reflects their formation and emission into the atmosphere in the full production cycle. The questions of definition of emission (carbon footprint) of carbon dioxide at soda ash production are considered. The differences of transit (indirect) and end-to-end emissions are shown. The calculations of through emission (carbon footprint) of soda ash and quicklime production are given. Based on chemical and thermochemical equations analysis and peculiarities of technological processes it was determined that the carbon dioxide net carbon footprint emission in soda ash production is 975 kg/t soda. The endto-end carbon dioxide emission in lime (calcium oxide) production is 1180 kg/t.

THE STUDY OF PROPERTIES OF SODA PRODUCTION WASTES AS ANTI-ICING REAGENTS

The article considers the possibility of reducing the man-made load on surface and ground waters in Lysychansk-Severodonetsk industrial agglomeration caused by numerous sludge collectors and tailings storage facilities of various industries formed many decades ago. The paper provides information on the location and technical condition of the sludge collectors of the liquidated "LYSSODA" manufacture (Luhansk oblast), the amount of waste currently stored in them as well as the impact of these wastes on the quality of groundwater in the area where the sludge collectors are located. The work shows one of several possible options for using such wastes as a valuable secondary mineral raw material for obtaining a marketable product. The averaged data on the chemical composition of the solid phase of sludge and indicators of the liquid phase composition are given. According to the results of the analysis of scientific and technical information, it has been found that such wastes can ultimately be used for the production of anti-icing reagents. The obtained results of research on the dependence of the freezing point of working solutions on the concentration of salts, including the added corrosion inhibitors (triethanolamine, hexamethylenetetramine), indicate the feasibility of using soda ash production waste to obtain effective liquid anti-icing reagents without a mechanical component, while the optimal amount of added corrosion inhibitors is 0.5% wt. Such reagents can be used both undiluted at temperatures up to minus 20oC and strengthened to 15-20% wt. by calcium chloride at temperatures up to minus 40°C with consumption on highways at the level of about 100 g/m2 of the treated surface.