Figure 5 - uploaded by Michael Styles
Content may be subject to copyright.
The range of compositions of ultramafic rocks and an indication of the proportion (area%) of the global abundance and the composition of the main rock types tested.
Source publication
Carbon dioxide capture and storage by mineralization has been proposed as a possible technology to contribute to the reduction of global CO2 levels. A main candidate as a feed material, to supply Mg cations for combination with CO2 to form carbonate, is the family of ultramafic rocks, Mg-rich silicate rocks with a range of naturally occurring miner...
Contexts in source publication
Context 1
... we have made a rough estimate of the volumes of the various types of geological bodies and the proportions of constitu- ent minerals. Th e total resource is around 90 terra tones (suffi cient to capture global emissions for 500 years), detail of the analysis will be the subject of a separate publication and a summary is shown graphi- cally in Fig. 5. Th e detail of the type of geological body is not of importance to this aspect of the study, only the proportions of the constituent minerals and their relative abundance. Th ese data show that serpen- tine and serpentine-olivine mixtures are volumetri- cally dominant on a global ...
Context 2
... experi- mental studies of mineral carbonation have largely concentrated on the simple olivine-rich or serpentine- rich end-members and the vast majority of ultramafi c rock compositions were untested. 4,10,13,31 Here we emphasize that many ultramafi c rocks consist of intimate mixtures of olivine, pyroxene and serpentine as shown in Fig. 5. For the testing program we tried to cover the whole spectrum of compositions using rocks as close as possible to the pure end members, together with intermediate compositions likely to be the largest potential source rocks on a global scale. Over 30 rocks were actually tested and those discussed in detail here are listed in Table 1 ...
Context 3
... For the testing program we tried to cover the whole spectrum of compositions using rocks as close as possible to the pure end members, together with intermediate compositions likely to be the largest potential source rocks on a global scale. Over 30 rocks were actually tested and those discussed in detail here are listed in Table 1 and shown in Fig. ...
Citations
... CO2 mineralization of relevant minerals is spontaneous and exothermal and occurs naturally as rock chemical weathering and subsequent atmospheric CO2 removal [20-23], but involves slow reaction rates. Over recent decades, numerous experimental methods and conditions for accelerating the CO2 mineralization of mineral or rock targets have been proposed (e.g., [24][25][26][27][28][29][30][31][32]). The methods include element extraction, mineral processing, and specific treatments using heat, pressure, and chemicals, which, unsurprisingly, require considerable energy consumption, infrastructure, and costs. ...
... Based on mineralogical variations, ultramafic rocks are divided into several groups, such as dunites, peridotites, pyroxenites, amphibolites, and serpentinites, which can also be subdivided into numerous types. Each type provides a specific amount of promising minerals that can affect the CO2 uptake potential [31,40,[47][48][49]. Besides the mineralogy, their microtextural characteristics, including the mineral grain size and the alteration level, additionally influence the CO2 mineralization potential when pursuing ERW strategies. ...
Ultramafic rocks are promising candidates for carbon sequestration by enhanced carbon dioxide (CO2) mineralization strategies due to their highly CO2-reactive mineral composition and their abundant availability. This study reports the mineralogy and microtextures of a representative ultramafic rock from the Ma-Hin Creek in northern Thailand and provides evidence of CO2 mineralization occurring through the interaction between CO2 and the rock in the presence of water under ambient conditions. After sample collection, rock description was determined by optical petrographic analysis. The rock petrography revealed a cumulated wehrlite comprising over 50% olivine and minor amounts of clinopyroxene, plagioclase, and chromian spinel. Approximately 25% of the wehrlite had altered to serpentine and chlorite. A series of CO2 batch experiments were conducted on six different rock sizes at a temperature of 40 °C and pressure of 1 atm over five consecutive days. The post-experimental products were dried, weighed, and geochemically analyzed to detect changes in mineral species. Experimental results showed that product weight and the presence of calcite increased with reducing grain size. Additionally, the modal mineralogy of the wehrlite theoretically suggests potential CO2 uptake of up to 53%, which is higher than the average uptake values of mafic rocks. These findings support the rock investigation approach used and the preliminary assessment of carbon mineralization potential, contributing to enhanced rock weathering techniques for CO2 removal that could be adopted by mining and rock supplier industries.
... CO2 mineralization of the promising minerals is spontaneous and exothermal and naturally occurs as rock chemical weathering and subsequent atmospheric CO2 removal [20][21][22][23], but it has slow reaction rates. Over decades, numerous experimental methods and conditions accelerating the CO2 mineralization of mineral or rock targets have been proposed (e.g., [24][25][26][27][28][29][30][31][32]). The methods include element extraction, mineral processing, and specific treatments using heat, pressure, and chemicals, which unsurprisingly require lots of energy consumption, infrastructure, and costs. ...
... Based on mineralogical variations, ultramafic rocks are divided into several groups, such as dunites, peridotites, pyroxenites, amphibolites, and serpentinites, which can also be subdivided into numerous types. Each type provides a specific amount of promising minerals that affects variable CO2 uptake potential [31,40,[47][48][49]. Besides the mineralogy, their microtextural characteristics, including mineral grain size, and alteration level, additionally influence the CO2 mineralization potential that can be applied to the ERW strategies. ...
Ultramafic rocks become promising candidates for carbon sequestration by enhanced carbon dioxide (CO2) mineralization strategies due to their highly CO2-reactive mineral composition and its abundant availability. This study reports a mineralogy and microtextures of a representative ultramafic rock from the Ma-Hin Creek in northern Thailand and observes evidence of CO2 mineralization occurring through the interaction between CO2 and the rock with the existence of water under ambient conditions. After sample collection, rock description was determined by optical petrographic analysis. The rock petrography reveals a cumulated wehrlite comprising over 50% olivine and minor amounts of clinopyroxene, plagioclase, and chromian spinel. Approximately 25% of the wehrlite has altered to serpentine and chlorite. A series of CO2 batch experiments were conducted on six different rock sizes at a temperature of 40°C and pressure of 1 atm over five consecutive days. The post-experimental products were dried, weighed, and geochemically analyzed to detect changes in mineral species. Experimental results showed that product weight and the presence of calcite increased with reducing grain size. Additionally, the modal mineralogy of the wehrlite theoretically suggests a potential CO2 uptake of up to 53%, which is higher than the average uptake values of mafic rocks. These findings support the suitable rock investigation approach and the preliminary assessment of carbon mineralization potential, contributing to enhanced rock weathering techniques for CO2 removal that could be adopted by mining and rock supplier industries.
... Thereby, lizardite serpentinites are ultramafic rocks that are most sensitive to carbonation. The same conclusion was made by Styles et al. (2014) who conducted experiments on leaching of diverse mineral types of ultramafic rocks. The higher temperature (230°С) experiments with СО 2 -bearing aqueous-salt fluid/ultramafic protolith are reported in (Klein and McCollom, 2013). ...
Abyssal peridotite outcrops compose vast areas of the ocean floor in the Atlantic, Indian, and Arctic Oceans, where they are an indispensable part of the oceanic crust section formed in the slow-spreading oceanic ridges (Mid-Atlantic Ridge, Southwest Indian Ridge, and Gakkel Ridge). The final stage in the evolution of abyssal peridotites in the oceanic crust is their carbonation, which they experience on the ocean floor surface or near it. The main goal of this study was to reconstruct the geochemical trends accompanying the carbonation of abyssal peridotites using MAR ultramafic rocks as an example and to identify the main factors that determine their geochemical and mineralogical differences. The composition variations of rock-forming minerals and their characteristic assemblages indicate that the initial stages of carbonation of abyssal peridotites occurred in crustal conditions simultaneously with the serpentinization of these rocks. The final stage in the crustal evolution of the abyssal peridotites is their exhumation on the ocean floor where they were brought up along the detachment faults. On the ocean floor, the abyssal peridotites in close association with gabbro form oceanic core complexes, and the degree of their carbonation sharply increases with time of their exposure on the ocean floor. The presented data made it possible to qualitatively reconstruct the sequence of events that determined the mineralogical and geochemical features of carbonatized abyssal peridotites of the MAR.
... This also applies to the 25 studies that report on the abundance of serpentine minerals, the most common being lizardite, chrysotile, antigorite and greenalite (e.g. Styles et al., 2014;Früh-Green et al., 2016). No mixed-layered clay minerals dominated by kaolinite or serpentine minerals occur within this grouping. ...
... (Buss et al., 2013;Elmi et al., 2017;Penkro et al., 2018;Plumlee et al., 2016). Only a limited number of investigations (7 in total) identify the mineral species, either as clinochlore or chamosite (Buatier et al., 2012;Styles et al., 2014;Boulton et al., 2014;Wang et al., 2015). Three types of chlorite-rich mixed-layer clay minerals included in this category (totalling 9 studies) are chlorite-smectite, chlorite-serpentine and chlorite-vermiculite (Drits et al., 2007;Zhang et al., 2015;Kameda et al., 2017;Cesarano et al., 2018). ...
... Despite the additional alteration that may occur during and after obduction onto continental crust, the ultramafic lithologies found in ophiolite complexes show similar states of reaction to the in-place oceanic crust with average phyllosilicate clay mineral contents between 27 and 84 wt% (Jambor et al., 2006;Petrounia, 2018). Their mineralogies are also similar and may contain lizardite, chrysotile, antigorite, clinochlore and some smectite (Styles et al., 2014). As most ultramafics of the oceanic crust have been sampled from fracture zones close to spreading ridges or from rocks subducted onto continental crust, there is a likelihood that quantifications overestimate the overall degrees of alteration occurring at the base of the oceanic crust. ...
Much work has been undertaken quantifying the abundance of phyllosilicate clay minerals in soils, sediments and rocks of Earth's crust. However, no detailed global compilation of these minerals has yet been presented. Such information has implications for understanding the interactions between weathering, soil formation, plate tectonics, climate change, diagenesis, low-temperature metamorphism and hydrothermal alteration. It is also central to understanding the distribution of bound (crystalline) and adsorbed water in upper crustal environments. This database presents the first clay mineral inventory based on mineral quantifications of 21 lithological units representing the brittle continental and oceanic crust characterised by varying degrees of water-rock interaction at temperatures between ∼ −25 and +350 °C. Published mineral abundances for >24,000 samples, determined largely by the Rietveld X-ray diffraction-based technique, indicates 21.5 weight% (wt%) of the brittle crust is composed of clay minerals: 12.9 wt% located in the upper (< 12 km) continental crust and 8.6 wt% in the thinner oceanic crust down to average depths of 6.57 km. In terms of clay mineral types, the 2:1 clay minerals with little or no expandability (commonly illite) are most abundant in Earth's upper crustal environments and total 7.7 wt%. The remaining 13.8 wt% is distributed more equally between the 1:1 kaolin-serpentine minerals (5.7 wt%), the highly expandable 2:1 smectites (3.0 wt%) and the 2:1:1 chlorites (5.1 wt%). Whereas continental soils and the underlying regolith represent only a small part of the clay mineral inventory (just 0.02 wt%), they do constitute important generating zones. These minerals and other products of surface weathering are redistributed to the main depositional sink located in sedimentary basins where 8.2 wt% of hydrous phyllosilicates reside and are modified during diagenesis or hydrothermal activity. A further 1.0 wt% are redistributed as oceanic sediment. The remaining 4.7 wt% of clay minerals in the continental crust are found in the altered igneous and crystalline rocks. Although less well quantified, the altered basalts, gabbros and ultramafic rocks of the oceanic crust, together with the overlying oceanic sediments, represent a significant part of the inventory characterised by notably high amounts of smectite, chlorite and serpentine minerals. The total amount of stored water (adsorbed and crystalline water) held in the inventory is equivalent in volume to 22% of today's surface water with approximately half located in altered oceanic crust. The trapping and release of surface water in and from the clay mineral sink likely influenced both interior crustal processes and climate change throughout Earth's history. On a shorter time scale, clay minerals aid climate stability by influencing atmospheric CO2 concentrations and the carbon cycle.
... Also, the conclusions from these studies contradicted one another. Styles et al. [40] conducted an acid leaching experiment of ultramafic rock with various mineral compositions in the presence of recyclable ammonium bisulphate under 100°C. Their results showed that the extent of magnesium leaching from high to low is in the order of lizardite serpentinite > serpentinised peridotites > olivine > antigorite serpentinite > pyroxene-and amphibole-rich rocks [40]. ...
... Styles et al. [40] conducted an acid leaching experiment of ultramafic rock with various mineral compositions in the presence of recyclable ammonium bisulphate under 100°C. Their results showed that the extent of magnesium leaching from high to low is in the order of lizardite serpentinite > serpentinised peridotites > olivine > antigorite serpentinite > pyroxene-and amphibole-rich rocks [40]. Bodénan et al. [38] analysed a coupled mechanical exfoliation and reactive carbonation on serpetinized dunite at 180°C, 1-2 MPa of CO 2 partial pressure (pCO 2 ) from 24 to 96 hours. ...
The heterogenous mineralogy of ultramafic mine waste rocks makes their carbonation rate hard to evaluate. This study investigated the effect of mineral composition on direct aqueous carbonation, through quantitative X-ray diffraction. The results show that magnesite was the main carbonated product, which was a stoichiometric conversion of forsterite. Diopside acted as a seed for quick crystallisation of magnesite. Lizardite could enhance the carbonation conversion, which reaches the optimum value when the weight ratio of lizardite to forsterite is 0.3-0.4. Sulphide in the reactant samples has a positive influence on carbonation. Brucite, magnetite and maghemite show little influence on carbonated products.
... The minimum and maximum supplies are also specified in the table. The impurity contents for biochar sources are based from the previous study of Belmonte et al. (2018), while the paper of Styles et al. (2014) is used to estimate the impurity contents in sources 3 and 4. Table 2 provides the CO 2 sequestration factors for all possible matches between a source ( i ) and a sink (j) and are based from Belmonte et al. (2018) for biochar and Strefler et al. (2018) for crushed alkaline rocks. Table 3 supplies the data for the sinks. ...
... Data for the sources (impurity limits are adapted fromBelmonte et al. (2018) andStyles et al. (2014)) ...
Biochar application and enhanced weathering are negative emission technologies (NETs) with the potential for large-scale deployment for the removal of CO2 from the atmosphere. Biochar is a solid product of pyrolysis that can permanently store carbon when applied in soil due to its chemical recalcitrance. Enhanced weathering is based on the acceleration of the natural reaction of moisture, CO2, and alkaline minerals. Both of these NETs rely on the application of pulverized material to different types of terrestrial sinks, which can include marginal and agricultural land. These two NETs can be used separately or concurrently, depending on local sink conditions. In some cases, simultaneous application of biochar and mineral powder to soil has the advantage of attaining additional beneficial effects of soil amendment. Although recent papers have reported the development of process integration models for optimizing carbon management networks based on either biochar application or enhanced weathering, none have reported models integrating these two NETs in the same system. To address this gap, a fuzzy mixed-integer linear programming model is developed that integrates biochar application and enhanced weathering for large-scale carbon sequestration. Fuzzy set theory provides a well-tested framework for integration of both subjectivity and uncertainty into mathematical programming. The model determines the optimal allocation of biochar and/or alkaline minerals from each source to each sink, while considering the application limits and CO2 sequestration potential. An illustrative case study is solved that clearly demonstrates the application of the model. The case study shows interesting results that can guide how the full sustainable potential of these two technologies can be utilized in a carbon management network.
Graphic abstract
... Farhang et al. investigated silica precipitation at different pH values and temperatures and determined that re-precipitation of silica retards dissolution of Mg by forming a diffusion barrier [30]. Dunite is partially weathered olivine that is the most abundant ultramafic rock available [31,32], which makes it important for the mineral carbonation process and needs significant consideration. Compared to other magnesium silicate minerals that have been studied for mineral carbonation, dunite is more complex as it is usually a mixture of minerals. ...
The aim of this study was to increase feedstock availability for mineral carbonation. Acid dissolution and carbonic acid dissolution approaches were used to achieve higher Mg extractions from peridotites. Acid dissolution studies of raw dunite, heat-activated dunite, heat-transformed dunite, and twin sister dunite have not been reported in the literature. Heat-activated dunite is more reactive as compared to heat-transformed dunite, raw dunite, and twin sister dunite. The fraction of magnesium extracted from heat-activated dunite was 57% as compared to 18% from heat-transformed dunite, 14% from raw dunite, and 11% from twin sister dunite. Similarly, silicon and iron extractions were higher for heat-activated dunite compared to that of heat-transformed dunite, raw dunite, and twin sister dunite. Materials rich in forsterite (twin sister dunite and heat-transformed dunite) showed preferential Mg release and exhibited incongruent dissolution similar to that of forsterite. Heat-activated dunite (amorphous magnesium silicate rich) on the other hand behaved differently and showed congruent dissolution. Olivine did not dissolve under carbonic acid dissolution (with concurrent grinding) and acidic conditions. Under carbonic acid dissolution with concurrent grinding conditions, olivine was partially converted into nanometer sized particles (d10 = 0.08 µm) but still provided 16% Mg extraction during 4 h of dissolution.
... As a result, 77 % dissolution efficiency was achieved by olivine while 100 % was obtained by serpentine [72,82]. Additionally, Styles et al. [88] found that magnesium dissolution efficiency of serpentinite could reach 78 %, but only 55 % with olivine. The mechanism behind this was investigated by comparing materials before and after leaching reaction through scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis [88]. ...
... Additionally, Styles et al. [88] found that magnesium dissolution efficiency of serpentinite could reach 78 %, but only 55 % with olivine. The mechanism behind this was investigated by comparing materials before and after leaching reaction through scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis [88]. It was found that the structures of magnesium silicates varied and olivine changed dramatically in post-experiment by the formation of secondary boussingaultite covering up the magnesium leaching sites. ...
Aqueous mineralisation is a process that reacts CO2 with aqueous ions to produce solid carbonates that fix CO2 permanently. Over the past decade, the commercial deployment of mineral carbonation processes has been slow, as many processes have been shown to suffer from limited reaction rate and poor energy efficiency. Yet, the potential of further improvement of this route, and its theoretical capacity to address CO2 emissions at the global scale, still drive efforts from many researchers in academia and industry. Aqueous CO2 mineralisation remains an attractive option, requiring milder process parameters than gas-solid mineral carbonation, and offers more opportunities for intensification through chemical additives, catalysts, process integration, use of alternative energy sources, reactor design, among other innovations. Aqueous mineral carbonation processes are categorized into three branches: (1) two-step carbonation process with dissolution stage; (2) direct aqueous carbonation with solid phase as reactant; (3) direct aqueous carbonation of brines. For each category, the progress made in the investigation and optimization of process parameters, source of feedstock, process intensification strategies, and products evaluation for utilisation, were assessed. Coupled with the process development, process simulation and reaction modelling, environmental impact assessment, energetic analysis, and economic evaluation, have also been critically reviewed. The focus was on identifying those processes with less energy and cost intensity and most CO2 avoided, to inform the most promising options for scale-up. This review discusses the feasibility of a portfolio of technologies, and updates the current process development status in bridging the gap between bench-scale investigation and industrial-scale implementation.
... In nature, the most abundant form of ultramafic rock is partially weathered olivine (Styles et al., 2012). Investigations into the mechanical activation of partially weathered olivine for mineral carbonation is of great significance to advance the technique and achieve adoption. ...
... Therefore it is good potential as raw material in production of silicon carbide (Hirasawa and Horita, 1987). If ex situ mineral carbonation is considered, Styles et al. (2014) found out that extraction rate of Mg from lizardite using 1.4M ammonium bisulfate has reached up to 80% after 1 hour. Similarly, Mg extraction from olivine could be gained up to 55%. ...
Geochemistry of ultramafic rocks in the Latowu Area of North Kolaka Regency, Southeast Sulawesi has been investigated with the aim at deciphering of mineral characteristics, chemical composition and their potential use as carbon dioxide storage. Mineralogy was characterized by both scanning electron microscopy (SEM) and X-ray diffractometry (XRD); whereas bulk rock and mineral chemistry were analyzed by means of X-ray fluorescence spectrometry (XRF) and Electron probe microanalyzer (EPMA) respectively. Results of analyses show that lizardite is predominant serpentine mineral present, followed by chrysotile and trace amount of magnetite. Remnants of olivine and pyroxene were detected in some samples but they have been pseudomorphicly replaced by serpentine. Serpentinization of Latowu ultramafic rocks has led to decrease in grain size and density. Lizardite is characterized by fine grained particles with higher in iron. The higher Mg and Fe of the rocks indicate a suitability as feed materials for carbon dioxide sequestration. Mineral and chemical properties of ultramafic rocks have significant role in evaluating the feasibility of mineral carbonation.
