Evaluating radiation risks and resource opportunities associated with phosphogypsum in the Philippines

Phosphogypsum (PG) accumulates during wet-phosphoric acid production for fertilizers. In the Philippines, PG is partly (40%) utilized to produce gypsum walls and cement. This work assesses the radiological risks and resource opportunities associated with PG stacks in the Philippines. The conducted in situ radiometric survey measured the activity concentrations of 40K, 238U, and 232Th at 270 locations. Besides, another 120 surface samples were collected. Pure PG exceeds the recommended radiation limits, but simple dilution with conventional materials can make PG available as an inexpensive secondary raw material for construction. PG further contains relevant concentrations of rare earths and Y (195 ppm).

Processing of waste slag of non-ferrous metallurgy for the purpose of its complex utilization as a secondary mineral raw material

This article provides an overview of the methods of processing slag from welting is given, different approaches and attempts of scientists from a number of countries aimed at processing such slags are considered. In the course of the review it was found that a huge number of the following methods and methods of processing from waelz slag, there is not a single option that has sufficient complexity of processing, and that at the moment are in the dumps toxins from waelz never found its use as a secondary raw material. The elemental chemical composition of the slag from welting, which is represented by compounds of calcium, silicon, iron, aluminum, carbon and heavy nonferrous metals in the form of zinc and lead, is determined. Thus, it is established that for many years, the slags from waelz that have not found their application and are in the dump at the moment continue to have a polluting effect on the environment. Ill. 1. Ref. 63.

Volcanic Tuff as Secondary Raw Material in the Production of Clay Bricks

The present work examines an innovative manufacturing technique for fired clay bricks, using tuff as a secondary raw material. Samples were made of clay and tuff (0–30 wt.%) fired at 900 to 1100 °C. The chemical and mineralogical compositions and physical and thermal analyses of raw materials were investigated by using SEM-EDS, RX and DTA-TG curves. The samples were analysed from the mineralogical, technological and mechanical points of view. The result show that the tuff’s presence in the clay mixtures considerably reduced the shrinkage of the product during the firing process, and the manufactured samples were of excellent quality. The compressive strength of the bricks varied from 5–35.3MPa, being influenced by the tuff content, clay matrix properties and firing temperatures. Finally, the heat demand for increasing the temperature from room to the firing temperature of the sample with 10% tuff content was 22%.

The New Chemically Resistant Material for the Invert Grouting Optimized by Secondary Raw Material

This paper deals with the development of a new mortar, for cement-based inverse grouting, with an increased degree of chemical resistance. The aim of this work is to verify new mixtures optimized by suitable secondary raw materials. The studied parameters include selected physical-mechanical characteristics and chemical resistance of individual raw material variants is characterized by resistance to sulfate solution. The results of this work show that it is possible to increase the chemical resistance by optimizing the grouting mortar mixture with suitable secondary raw materials. The optimized mixture for the new grout will be part of a comprehensive material system for the remediation of sewers or shafts.

Estimation of the volume of metal waste generated during ship recycling

In the case of a long-term stagnation of the ship, before being transferred for disposal, its structures are exposed to the environment and, as a result, are destroyed. Ultimately, this leads to the fact that part of the metal becomes unsuitable for further use, even as a secondary raw material, and will be sent to waste, which must be buried in a certain way, leading the treatment in accordance with current standards. The presence of waste will reduce the mass of metal that is sent for processing, and, consequently, brings profit to the ship recycling yards. The article considers an approach that allows us to estimate the volume of waste and the reduction in the mass of "useful" metal, both in general terms and numerically for a specific ship project. Equations are obtained that allow determining the mass of spent metal, both in operation and in long-term stagnation of the ship.

The Potential for REE and Associated Critical Metals in Karstic Bauxites and Bauxite Residue of Montenegro

Research for critical raw materials is of special interest, due to their increasing demand, opulence of applications and shortage of supply. Bauxites, or bauxite residue after alumina extraction can be sources of critical raw materials (CRMs) due to their content of rare earth elements and other critical elements. Montenegrin bauxites and bauxite residue (red mud) are investigated for their mineralogy and geochemistry. The study of the CRM’s potential of the Montenegrin bauxite residue after the application of Bayer process, is performed for the first time. Montenegrin bauxites, (Jurassic bauxites from the Vojnik-Maganik and Prekornica ore regions from the Early Jurassic, Middle Jurassic-Oxfordian and Late Triassic paleorelief) are promising for their REE’s content (around 1000 ppm of ΣREE’s). More specifically, they are especially enriched in LREEs compared to HREEs. Regarding other CRMs and other elements, Ti, V, Zr, Nb, Sr and Ga could also be promising. In bauxite residue, the contents of Zr, Sr, V, Sc, La, Ce, Y, Ti and Nb are higher than those in bauxites. However, raw bauxites and bauxite residue as a secondary raw material can be considered as possible sources of CRMs.

Mathematical modelling of ultrasonic treatment of asphaltene deposits

Objective. The removal of asphaltene deposits at oil and gas facilities is one of the urgent and important problems and requires significant material and labor costs. It is possible to reduce costs by creating and implementing effective technical means, which requires an in-depth study of the processes of organic matter deposition at oil and gas facilities and their use as a secondary raw material. Methods. This paper discusses modern views on the state of the problem of asphaltene deposits in oil shipping and storage equipment and possible ways to solve it. The paper provides an overview of various ways to clean shipping and storage objects from asphaltene deposits: chemical (adding additives, solvents), thermal (heating by special devices or injection of superheated steam during exploitation), mechanical (using scrapers and pistons), and refers, among other things, to scientific works on the use of ultrasound to accelerate the removal of deposits. Results. The paper considers methods for removing deposits, as well as using the positive effect of the removed layer as a secondary energy source. A procedure for model calculation of the use of ultrasonic equipment to remove deposits has been developed. As a result, the deposit melting front velocity was determined depending on the duration of exposure. Conclusion. Taking into account the positive world experience, the level of development of the ultrasonic method for removing asphaltene deposits in the oil and gas industry and the use of asphaltene deposits as a secondary raw material, this area needs further development. The widespread implementation of equipment and, from the standpoint of rational use of natural resources, the use of deposits as a secondary raw material will increase cost efficiency and equipment efficiency, and reduce environmental impact.

ON USING VOLGA-CASPIAN ZANDER’S CHEEKS IN PRODUCTION OF CANNED FISH BABY FOOD

The article considers the purpose of the research as defining the possibility of using recycled fish raw material (zander’s cheeks and fat) in production of canned fish baby food. The components of the developed pasteurized canned fish “Sudachok” (heads and cheeks of pike perch, blanched carrots, oatmeal or buckwheat flour, fat from zander’s intestine, concentrated fish broth prepared from zander’s head and vertebral bones) were tested for the concentration of fat, protein, carbohydrates; zander’s muscle tissue - for the concentration of essential amino acids. It was determined that zander’s cheeks make up 4.4 - 8.8% of head’s mass, they being high-protein tissue (protein content is more than 19%), low-fat (fat content is 0.7%) secondary raw material and contain non-protein nitrogen (NPN), where formol and titrate nitrogen (FTN) and volatile bases nitrogen (VBN) are 370.5, 39.3 and 8.0 mg/100g, respectively. Formulations were developed and the pasteurized fish cans for babies were produced using zander’s cheeks and vegetable components (carrots, oatmeal flour, or buckwheat flour), fat and concentrated broth from boiling zander’s head bones. The composition has an optimized protein and fat content. In terms of quality, the pilot samples of canned fish with the corrected number of individual components of the recipe were found to meet the requirements of All-Union State Standard 29276 “Canned fish for baby food”.