Characterization of Persian lime production (Citrus x latifolia; Tanaka ex Q. Jiménez)

O Objective: To characterize the production system of Persian lime (Citrus x latifolia; Tanaka ex Q.Jiménez) in Martínez de la Torre, Veracruz, Mexico. Design/Methodology/Approach: A semi-structured survey was applied with 50 Persian lime producers, through a directed sample. For this study a logistic regression was conducted: logit model, through measurement of the binary or dummy dependent variable, where the dependent variable takes values of “0 and 1”. Results: Lime producers are mostly men with an average age of 54 years, the type of property is ejido and they have been producing lime from 15 to 30 years, the knowledge used for the production are rainy periods and soil fertility. Most use intolerant rootstock. Regarding the econometric result, variables with higher significance were obtained that are related to the dependent variable. Study Limitations/Implications: It offers elements for the production of Persian lime. Conclusions:Finally, there is low participation of women in agricultural tasks. When it comes to the application of fertilizers, prun

Materials From Hazardous Iron Ore Treatment Waste, Concrete Demolition Debris And Lime Production Waste to Increase Environmental Sustainability of Industrial Regions

To prevent environment pollution by hazardous industrial dumps of iron ore treatment sludge, concrete production/demolition debris and lime production waste sustainable cement-less construction materials were developed for substitution of traditional natural raw components excavated in careers, irreversibly destroying natural bonds. Their ​​ axial resistance values on the 3rd day of hydration were till 2.34 MPa, on the 28th day - up to 3.94 MPa, on the 180th day 8.40 MPa and on the 365th day 10.22 MPa. The expanding coefficient on the 3rd day were till 2.13%, 2.51% on the 28th day, and on the 365th day 2.22%. Water absorption on the 28th day was 7.17 - 9.32% and decreases to 6.26 - 8.64% on the 90th day. All these characteristics correspond to the Brazilian norms. The physical - chemical processes of materials’ structures formation included alkaline dissociation of solid particles’ surface, with sol appearing and densification till transition to gel. Long-lasting gel compaction and densification to stone-like condition made its structure similar to natural rock materials - silica, opal, obsidian, perlite, pumice, amber, flask, etc. They can be used for production of road bases, concrete blocks and solid unburned bricks, among other sustainable construction materials.

Antioxidant Activity of Non-Volatile Lime (Citrus aurantifolia Swingle) Extract

The paper reports the antioxidant activity of a non-volatile fraction of lime processing byproducts from the lime syrup home industry. The activity was measured by spectrophotometry to obtain the 50% inhibition concentration (IC50) using the 2,2- diphenyl-1-picrylhydrazyl (DPPH) method. The sample was extracted by the maceration method with n-hexane, ethyl-acetate, and ethyl-ethanol. The IC50 values of 681 ppm, 458 ppm, and 2,775 ppm were n-hexane, ethyl-acetate, and ethyl-ethanol. The experiments concluded that the ethyl-acetate extract provides the best inhibition value to scavenge free-radicals DPPH. The HPLC and mass spectroscopy were measured to find out the content and group of active compounds. The significant compounds consisted of naringin, poncirin, or neoponcirin, which are known as antioxidant substances. The result shows the potential application of the lime by-products, its volatile fraction, and the nonvolatile fraction, which is the production residue of lime peel. This work can be applied as an alternative to zero-waste lime production, which may benefit the industry and the environment.

Developing an Industrial Symbiosis of Chemical Industries: a Case Study

The article considers the approaches to building a circular economy based on the example of a functioning Russian industrial hub. Among the features analyzed are the specificities of the industrial symbiosis development of chemical enterprises and material flows that link different technical processes, namely the production of soda ash, lime, salt, and gypsum. This study assesses the pollutant emissions from the new technical processes and the use of accumulated chrome production wastes as secondary material resources. Likewise, the article demonstrates the possibility of direct absorption of carbon dioxide, as a byproduct of lime production during soda ash manufacturing. The study ends with recommendations for considering the aspects for the use of secondary resources in determining the sectoral and inter-sectoral best available techniques. Similarly, it sheds light on possibilities for optimizing the system of technological regulation and general binding rules application for managing insignificant environmental aspects of industrial production.

Modeling of lime production process using artificial neural network

Lime is a significant material in many industrial processes, including steelmaking by blast furnace. Lime production through rotary kilns is a standard method in industries, yet it has depreciation, high energy consumption, and environmental pollution. A model of the lime production process can help to not only increase our knowledge and awareness but also can help reduce its disadvantages. This paper presents a black-box model by Artificial Neural Network (ANN) for the lime production process considering pre-heater, rotary kiln, and cooler parameters. To this end, actual data are collected from Zobahan Isfahan Steel Company, Iran, which consists of 746 data obtained in a duration of one year. The proposed model considers 23 input variables, predicting the amount of produced lime as an output variable. The ANN parameters such as number of hidden layers, number of neurons in each layer, activation functions, and training algorithm are optimized. Then, the sensitivity of the optimum model to the input variables is investigated. Top-three input variables are selected on the basis of one-group sensitivity analysis and their interactions are studied. Finally, an ANN model is developed considering the top-three most effective input variables. The mean square error of the proposed models with 23 and 3 inputs are equal to 0.000693 and 0.004061, respectively, which shows a high prediction capability of the two proposed models.

Human Footprints in the Karst Landscape: The Influence of Lime Production on the Landscape of the Northern Dalmatian Islands (Croatia)

Throughout history, the production of lime on the Croatian islands, which are mostly made of limestone and dolomite, has been an important economic activity. In the northern Dalmatian islands, which are centrally positioned on the northeastern Adriatic coast, lime was produced for local needs, but also for the purposes of construction in the nearby cities of Zadar and Šibenik. On the basis of research into various written and cartographic archival sources relating to spatial data, in addition to the results of field research, various traces of lime production have been found in the landscape of the northern Dalmatian islands. Indications of this activity in the insular karst are visible in anthropogenic forms of insular relief (lime kilns, small quarries, stone deposits) and in degraded forms of Mediterranean vegetation. This activity has also left its mark on the linguistic landscape in the form of toponyms, indicating that lime kilns were an important part of the cultural landscape.

CONSTRUCTIVE DESIGN AND FEATURES OF THE PROCESSES IN THE ROASTING SHAFT FURNACES BY USING GASEOUS FUEL

The article analyzes shaft furnaces for lime production. According to the method of firing, shaft furnaces are of bulk type, semi-gas type, gaseous and liquid fuels. The disadvantages of the operation of the main modern kilns during lime burning have been established. The main aggregates for high-tonnage lime production are mine lime kilns, in which blast furnace coke or anthracite, or high-quality coals are used as fuel. Generally, lean fuels are used in industries where, together with the technological cycle, carbon dioxide is used, which are contained in flue gases with a concentration of 36−40%mass. The data on the operation of six furnaces on the territory of Ukraine at the enterprises showed that gas shaft furnaces of cylindrical and slotted type with a straight-lining profile were widely used. The parameters of such furnaces are productivity from 100 to 250 tons per day, shaft diameter from 3.2 to 5.4 m, and height 6−8 furnace diameters. Most often, they use heating systems with central and two rows of peripheral injection burners without protrusion. The most critical part of all furnaces is the distribution of gas flow rates over the cross-section of the furnace shaft and the depth of radial penetration of the gas flow into the material layer. Calculations of τ1 and τП were carried out in the following way: for τ1, the temperature range of the medium was chosen from 1300 to 250−300 °С, τox − the temperature range for the material was chosen from 1000 to 100 °С and the density of the product was taken into account at the degree of decomposition of limestone 98% (=1700 kg/m3). In the preheating zone, the limiting stage is the supply of heat from the gas to the lump material, and at the same time can be taken equal to ⁓400−450 kJ/(m2∙h∙К) and τ1 is estimated as 0.8÷1 hour. The total residence time of the material in the furnace (in the heating zone and in the firing zone) is estimated at 1.4÷1.5 hours. The average speed of material movement in the cylindrical part of the furnace is estimated as 0.004 m/s, which makes it possible to consider the filtering layer conditionally stationary. These characteristics affect the quality of limestone and the uniformity of limestone firing that was the basis for the design of roasting shaft kilns using gaseous fuel.