Search results for " Mineral recovery"
showing 6 items of 6 documents
Valorisation of SWRO brines in a remote island through a circular approach: Techno-economic analysis and perspectives
2022
Nowadays, small remote islands rely heavily on desalination technologies to overcome freshwater scarcity. Unfortunately, these technologies are accompanied by the production of brines which can affect the receiving water bodies i.e., the aquatic ecosystem. Yet, it is extremely appealing how such brines constitute an abundant source of valuable raw materials (such as magnesium). In this work, a novel hybrid system is introduced to capture the value of seawater reverse osmosis (SWRO) brines produced in the minor Sicilian island of Pantelleria. The “Minimal Liquid Discharge” (MLD) process consists of: (i) Nanofiltration NF (separation of bivalent from monovalent ions), (ii) Mg Reactive Crystal…
A continuous plug flow reactor for magnesium recovery from concentrated brine
2015
Magnesium is one of the eight most abundant elements on the world and the third most abun- dant in the sea, buc practically only two countries (Russia and China) control the world market for this compound. Product purity, Mg recovery, crystal morphology and granulometric distribution of precipitated particles were examined through careful laboratory analysis and results from different tests were compared, in order to identify the effect of allcaline species’ nature and concentration on precipitation phenomena.
High purity recovery of magnesium and calcium hydroxides from waste brines
2021
Direct disposal of concentrate brines, generated by many industrial sectors, causes serious environmental concerns. An industrial sector that produces high concentrate brines is softening water industry, in particular during the regeneration of ion exchange resins. These brines are mainly rich in sodium, magnesium and calcium chlorides, thus, their regeneration, by removal/recovery of magnesium and calcium, can be a valuable option to turn the brine into a source of minerals and reduce disposal costs and environmental concerns. In this regards, one of the goals of EU-funded ZERO BRINE project is to develop a treatment chain for the valorization and regeneration of spent brines from water so…
Evaluation of the Purity of Magnesium Hydroxide Recovered from Saltwork Bitterns
2022
Magnesium has been listed among the 30 critical raw materials by the European Union. In recent years, many green and sustainable alternative Mg2+ sources have been sought to satisfy the EU’s demand and to avoid mineral ore consumption. In this context, saltwork bitterns, the by-products of solar sea salt production, have attracted much attention thanks to their high Mg2+ concentrations (up to 80 g/L) and low Ca2+ and bicarbonate contents (<0.5 g/L). Although investigations on Mg2+ extraction from bitterns in the form of Mg(OH)2(s) have already been performed, product purity has never been properly addressed. Mg(OH)2(s) is a chemical compound of great interest and extensive utility in num…
Magnesium recovery from exhausted brine
2015
Mg and MgCO3 are among the 20 EU critical raw materials. Interestingly, Mg can be found at very high concentration in brines generated as waste stream from salt works. Literature works have demonstrated the feasibility of Mg extraction from brines [1–3] by reactive precipitation, for the production of Mg(OH)2. Here we present an overview of the experimental campaigns carried out using exhausted brine from real salt works (Italy) to produce Mg(OH)2 with high purity and conversion. Lab – and pilot-scale batch and semi-continuous CSTR crystallisers were developed and tested, eventually leading to a continuous process by a quasi-PFR pilot reactor. Different alkaline solutions have been adopted …
Analysis of particles size distributions in Mg(OH)2 precipitation from highly concentrated MgCl2 solutions
2022
Magnesium is a raw material of great importance, which attracted increasing interest in the last years. A promising route is to recover magnesium in the form of Magnesium Hydroxide via precipitation from highly concentrated Mg2+ resources, e.g. industrial or natural brines and bitterns. Several production methods and characterization procedures have been presented in the literature reporting a broad variety of Mg(OH)2 particle sizes. In the present work, a detailed experimental investigation is aiming to shed light on the characteristics of produced Mg(OH)2 particles and their dependence upon the reacting conditions. To this purpose, two T-shaped mixers were employed to tune and control the…