Towards Zero Solid Waste in the Sedimentary Phosphate Industry: Challenges and Opportunities

The phosphate industry produces huge volumes of waste (hundred million tons per year). These wastes are generally surface landfilled, leading to significant environmental impacts and a large footprint. The current practices of phosphate waste management, the typology of the waste streams and their characteristics, and finally their potential applications are reviewed. All the waste streams generated during the life cycle of phosphoric acid production going from the extraction of phosphate rock to its enrichment and transformation are considered. Great circularity opportunities have been identified and they aim (i) to recover the residual phosphorus and other critical minerals and metals, and (ii) to consider phosphate wastes as alternative resources in the civil engineering and building sectors. The purpose is to shift from linear thinking to circular thinking where synergy between different mining and other industries is highly encouraged. By doing so, opportunities to safeguard natural resources and to minimize the environmental and societal impacts are limitless. However, many challenges are still limiting this shift: economic and technical constraints, societal and policy-makers’ awareness, regulation harmonization and finally knowledge gaps. More efforts and investment in research and development are still required to reach the zero-waste target.

Enzymatic Degumming of Rice Bran Oil Using Different Commercial Phospholipases and Their Cocktails

Rice bran oil is a highly nutritious vegetable oil, as it is rich in tocols and γ-oryzanol. Degumming is the first step in the vegetable oil refining process, and its main objective is the removal of phospholipids or gums. In the present study, enzymatic degumming trials were performed on crude rice bran oil using the phospholipases PLA1, Purifine® PLC, their mixture (PLA1/PLC), and a cocktail known as Purifine® 3G. Enzymatic degumming applying 50 mg/kg of PLA1 for 120 min resulted in a residual phosphorus content of 10.4 mg/kg and an absolute free fatty acid increase of 0.30%. Enzymatic degumming applying 300 mg/kg of Purifine® PLC for 120 min at 60 °C resulted in a residual phosphorus content of 67 mg/kg and an absolute diacylglycerol increase of 0.41%. The mixture of phospholipases and the cocktail presented approximately 5 mg/kg of residual phosphorus content after the reaction times. For all degumming processes, the preservation of minor components such as tocols and γ-oryzanol were observed. These results indicate that the use of enzyme mixtures or their cocktails to attain low phosphorus content and high diacylglycerol/free fatty acid conversion during enzymatic degumming is a viable alternative.

KME Cu-DHP

KME Cu-DHP is a phosphorus-deoxidized copper that contains a minimum of 99.90% copper and high residual phosphorus. The electrical conductivity of this type of copper is relatively low on account of the high phosphorus content. KME Cu-DHP possesses very good formability and joining properties and is resistant against hydrogen embrittlement. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and bend strength. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Cu-923. Producer or source: KME Germany GmbH.

KME Cu-DLP

KME Cu-DLP is a phosphorus-deoxidized copper that contains a minimum of 99.90% copper and a small amount of residual phosphorus. Owing to the presence of residual phosphorus the electrical conductivity of KME Cu-DLP is lower than that of the high-conductivity and oxygen-free coppers (Cu-ETP, Cu-FRHC, and Cu-OF). This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming and heat treating. Filing Code: Cu-917. Producer or source: KME Germany GmbH.

AURUBIS Cu-HCP

Aurubis Cu-HCP is a deoxidized, oxygen-free copper with a low residual phosphorus content. It combines very good formability and joining characteristics with high electrical conductivity (98% IACS minimum). This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as heat treating. Filing Code: Cu-916. Producer or source: Aurubis AG.

AURUBIS Cu-PHC

Aurubis Cu-PHC is a deoxidized, oxygen-free copper with a very low residual phosphorus content. It combines good electrical conductivity with excellent hot and cold formability and excellent joining characteristics. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as heat treating and joining. Filing Code: Cu-915. Producer or source: Aurubis AG.

Second-crop cowpea under residual phosphorus doses in the Brazilian Amazon

ABSTRACT The southeastern mesoregion of the Brazilian Pará state is an important soybean producer, and the second-crop system can increase the local agricultural production. However, Latosols with medium to very clayey texture predominate in the region and, despite being suitable for farming, they naturally have low levels of available phosphorus (P). This study aimed to evaluate the yield of second-crop cowpea [Vigna unguiculata (L.) Walp] under doses of residual P in a Yellow-Latosol. Two experiments were installed under field conditions. The experimental design was randomized blocks, with five treatments (residuals of 0, 50, 100, 150 and 200 kg ha-1 of P2O5) and four replications. The first experiment consisted of cultivating second-crop cowpea after the soybean harvest, with phosphate doses provided during the soybean planting, and the second of second-crop cowpea after the rice harvest, with phosphate doses provided during the rice planting. The 1,000-grain weight and production of pods, husks and grains were evaluated. The production of pods and husks were higher in the area with residual P. The highest yield was obtained in the residual dose of 200 kg ha-1 of P2O5, reaching a grain yield of 1,256 kg ha-1 after the soybean harvest and 885 kg ha-1 after the rice harvest.