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Mitigation of colloid clay particles is critical during flotation and flocculation processes in mineral processing. Most organic and inorganic mitigation reagents have negative impacts on the environment and human health; therefore, biologically derived substances have been attracting attention as alternative reagents. Given the anisotropic nature of clay surfaces, it is imperative to understand reagent adsorption on the individual edge and basal plane surfaces of clays. Quartz crystal microbalance with dissipation (QCM-D) was used in this study to determine the adsorption characteristics of three biopolymers (the protein-based biopolymer, lysozyme, and protein and polysaccharide-based oligomers; protamine and pectin) on model surfaces of the anisotropic edge and basal planes of the clays (e.g., kaolinite and serpentine). SiO

Aqueous dispersions of geometrically anisometric nano sized sodium-montmorillonite (Na-Mt) display a sol–gel transition at very low solids concentrations. The microstructure of the gel formed at very low ionic strengths is considered electrostatically repulsive with a nematic character, and the gel state at ionic strengths where Debye length is of the order of particle size is conjectured to be physical aging free. Here, we investigate the true nature of osmotically prepared Na-Mt dispersions at low ionic strength (~10-5 M), below and above the gel point. The sol phase exhibited very low yield stress than the gel state, without any sign of physical aging, thus behaving as a equilibrium state. In contrast, the gel exhibited signatures of physical aging, that is, an evolving microstructure which consolidates with time when left undisturbed thus behaving as out of equilibrium state. The physical aging behaviour becomes more pronounced at Na-Mt concentrations far above the gel point. A critical shear rate existed, below which no stable flows were possible in the gel state representing the microstructural reorganization timescale. Overall, Na-Mt dispersions in the gel state behaves as out of equilibrium systems with an ever-evolving microstructure, in opposition to the assumption that low ionic strength Na-Mt gels are an equilibrium phase. The possible origin of physical aging such as reversible orientation of Brownian anisotropic particles, stiffening of an existing microstructure or reorganization of microstructure towards minimal energy configuration has been discussed in detail.

Non-renewable chemical reagents are commonly used as dispersants or flocculants of phyllosilicate clay particles in several industrial fields such as water/wastewater treatment, food production, papermaking, and mineral processing. However, environmentally benign reagents are highly desired due to the non-biodegradability and negative impacts of synthetic reagents on aquatic life. In this work, the dispersion and flocculation behavior of sustainable polymers (anionic and cationic biopolymers) sourced from proteins and polysaccharides were studied in serpentine phyllosilicate suspensions using the following bench-scale tests: zeta potential, microflotation, settling and turbidity, and isotherm adsorption using total organic carbon. The anionic polysaccharide-based biopolymer pectin acted as a switchable biopolymer for serpentine. That is, it could switch from being an efficient flocculant at pH 7 to an effective dispersant at pH 10.

Kaolinite particles are geometrically anisometric and electrostatically anisotropic. Until recently, the charge of both basal faces of kaolinite was assumed to be independent of pH, and the isoelectric point (IEP) of the edge surface was thought to occur at pH 4–6. Therefore, kaolinite suspensions were expected to have an edge–face association at low pH. However, recent atomic force microscopy (AFM) studies have shown that the kaolinite alumina basal face and edge surface carry a pH-dependent surface charge with an IEP at pH 5–6 and ∼ 3, respectively. Here, we revisit the modes of particle association in kaolinite suspensions and apply Derjaguin–Landau–Verwey–Overbeek (DLVO) theory to study the rheological implications of surface charges of various kaolinite faces from recent AFM-based studies. Specifically, aging within the linear viscoelastic region, small amplitude oscillatory shear behavior (strain amplitude and frequency response), and critical stress behavior were studied as a function of pH. Kaolinite suspensions (40 wt%) exhibited two-step structure recovery after shear rejuvenation and two-step yielding at pH less than the IEP of the alumina basal face. In addition, the storage modulus (G′) and critical stress required to stabilize the flow followed non-monotonic behavior as a function of pH. At low pH, the silica face–alumina face mode of association was expected to be dominant rather than the edge–face microstructure. A peak in the G′ vs. pH curve at pH 4.5–5 was correlated with the silica face–alumina face attraction estimated from DLVO theory, which passes through a maximum at approximately the same pH. Based on these observations, we propose a qualitative state diagram for kaolinite suspensions in the pH-concentration space.

Sodium-montmorillonite (Na-Mt) particles are geometrically anisometric that carry a pH dependent anisotropic surface charge. Therefore, it should be possible to manipulate the particle-particle interaction of colloidal range Na-Mt suspensions through pH changes which in turn should alter the soft glassy dynamics of Na-Mt suspensions.Rheological experiments were used to probe the impact of pH mediated colloidal particle-particle interaction on the physical aging, linear viscoelastic response, and yield stress behavior of Na-Mt suspension.The temporal evolution of the storage modulus (G') was stronger in the acid regime (pH 9.5) than the base (pH ≥ 9.5) pH regime. Horizontal shifting of the aging curves in the acid and base regimes led to aging time-H

A proof-of-concept for the carbonation-assisted processing of ultramafic nickel ores is presented. Carbonation converts serpentine, the primary gangue or undesirable mineral, to magnesite. It prevents slime coating of fine gangue minerals on pentlandite, the main nickel-bearing mineral, during froth flotation, and improves nickel recovery and concentrate grade. Additionally, CO2 is captured and stored in the form of solid carbonates, thus removing it from the atmosphere. Microflotation experiments demonstrated improved nickel recovery (61.2 to 87.4 wt%) and concentrate grade (20.6 to 24.7 wt%) in carbonated vs. uncarbonated systems. The mechanism behind the improved nickel flotation was investigated by zeta potential measurements, optical imaging microscopy, X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry. These analyses confirmed the absence of slime coating in the carbonated system under the flotation conditions tested. Finally, a preliminary techno-economic analysis was performed to evaluate the cost metrics of incorporating carbonation into nickel mineral processing.

Bioelastomers have been extensively used in tissue engineering applications because of favorable mechanical stability, tunable properties, and chemical versatility. As these materials generally possess low elastic modulus and relatively long gelation time, it is challenging to 3D print them using traditional techniques. Instead, the field of 3D printing has focused preferentially on hydrogels and rigid polyester materials. To develop a versatile approach for 3D printing of elastomers, we used freeform reversible embedding of suspended prepolymers. A family of novel fast photocrosslinakble bioelastomer prepolymers were synthesized from dimethyl itaconate, 1,8-octanediol, and triethyl citrate. Tensile testing confirmed their elastic properties with Young's moduli in the range of 11-53 kPa. These materials supported cultivation of viable cells and enabled adhesion and proliferation of human umbilical vein endothelial cells. Tubular structures were created by embedding the 3D printed microtubes within a secondary hydrogel that served as a temporary support. Upon photocrosslinking and porogen leaching, the polymers were permeable to small molecules (TRITC-dextran). The polymer microtubes were assembled on the 96-well plates custom made by hot-embossing, as a tool to connect multiple organs-on-a-chip. The endothelialization of the tubes was performed to confirm that these microtubes can be utilized as vascular tubes to support parenchymal tissues seeded on them.

Worldwide high-grade nickel sulphide deposits are being depleted and new ones are not being discovered. Therefore, the exploitation of low-grade ultramafic nickel ores is of increasing interest. Processing these deposits, however, is a challenge, due to the high serpentine content. Serpentine minerals are anisotropic, increase the viscosity of ore slurries, dilute the concentrate, and slime-coat the valuable nickel mineral pentlandite. Microwave pre-treatment of ultramafic nickel ores has been proposed to convert the serpentine to olivine, reduce the viscosity of the ore slurry, improve ore grindability and mineral liberation, and reduce the overall energy requirements of processing. To optimize the process, an understanding of the microwave heating properties of ultramafic nickel ores and constituent minerals is necessary. The microwave heating of serpentine and olivine, the primary components of ultramafic nickel ores, is explored in this paper. Microwave heating tests and high-temperature microwave properties (real and imaginary permittivity) analysis were performed. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) tests were also completed to explain the permittivity data. Serpentine responded more readily to microwaves than olivine and the maximum temperatures achieved were 216 °C and 57 °C, respectively. Serpentine did not reach the temperature required for dehydroxylation (600-700 °C). The real and imaginary permittivities for serpentine and olivine varied with temperature, but overall were low, indicating these minerals cannot be expected to heat well on their own upon exposure to microwave radiation. A microwave susceptor is required for the serpentine in ultramafic nickel ores to reach dehydroxylation temperatures. It is hypothesized that the small quantities of pyrrhotite and magnetite present in ultramafic ores play this role.

The volume of a supercritical CO2 droplet on limestone and sandstone substrates in different solutions (electrolyte solutions and saturated saline water) at 1500 Psi and 40 °C was determined as a function of immersion time using a high pressure pendant/sessile drop cell. To differentiate the storage of the supercritical CO2 by residual trapping into the pores from the dissolution in bulk solutions, the measurement was also conducted using a non-porous silica wafer. The limestone, sandstone and silicon wafer were all initially water-wet, with the silicon wafer becoming more CO2-wet over time. Limestone and sandstone were slightly more CO2-wet compared to the SW, which would affect the mobility of CO2. The volume reduction of the CO2 droplet was observed to be much more rapid on porous substrates than on nonporous silica wafer due to the residual trapping (storage) of CO2 into the pores. Residual trapping was found to dominate the kinetics of CO2 storage, especially throughout the initial 10 min of the experiment.

In the last few decades there has been increasing interest in the application of microwaves as an energy source in extractive metallurgy for the treatment of ores and concentrates. The fundamental parameters required for the design of industrial systems are the real and the imaginary permittivities, which are both frequency and temperature dependent. However, there is a dearth of data on the permittivities, of not only the ores and the concentrates, but also the minerals that comprise the ores. In the present research, the permittivities of selected hydroxide minerals were determined using the cavity perturbation technique as a function of both temperature and frequency. The behaviours of the permittivities were interpreted using both thermogravimetric analysis (TGA) and thermodynamic modelling. The water in these minerals, in its various forms, makes a significant contribution to the permittivities. Also, generally, the higher iron-bearing hydroxides have higher permittivities than the magnesium silicates or aluminosilicates. It is shown that the permittivities of the hydroxide minerals are low, but the hydroxyl ion makes a significant contribution. The effect of frequency is more pronounced both during dehydroxylation and at high temperatures and, in both cases, is attributed to increases in the ac conductivity.

The mining of ultramafic ores is required to meet society’s continued demand for nickel. These deposits, however, are difficult to process due to their high serpentine content. Serpentine, a gangue mineral, increases slurry viscosity, slime-coats the valuable Ni-bearing mineral pentlandite, and reports to and dilutes the froth during flotation via the formation of bubble-fibre aggregates. Microwave pre-treatment can be used to convert the serpentine gangue to olivine, which should improve ore processing. However, the fundamental microwave properties and heating behaviour of ultramafic ores must be understood to develop a robust process. Microwave heating curves were developed for, and high temperature permittivity analysis was conducted on, two ultramafic nickel ores (Pipe and OK ore). Subsequently, TGA/DSC (thermogravimetric analysis/differential scanning calorimetry) and HTXRD (high-temperature x-ray diffraction) tests, along with a thermodynamic analysis using FactSage 7.3, were done to explain the heating behaviours and permittivity data. An unusual peak in the permittivity data was detected at 950 °C for the Pipe ore with both increasing and decreasing temperature; however, no phase transitions were detected in the TGA/DSC analysis. HTXRD of the Pipe ore revealed the presence of heazlewoodite at higher temperatures (950 to 1100 °C). Thermodynamic modeling of the Pipe ore system suggests that melting at higher temperatures is responsible for the decrease in the permittivities of this ore. To mitigate the melting and clumping of the ore particles, it is necessary to ensure that the processing temperature does not exceed 800 °C during microwave treatment. The OK ore, which contained less microwave response minerals than the Pipe ore, reached a maximum temperature of 500 °C after only 5 min of heating time, and therefore overheating was not an issue.

An impending retirement has led us to reevaluate the course: should we keep it - and if so who teaches it, or should we look to change it? The course was co-taught with a new faculty member, coupled with internal reviews and discussions. Ultimately, we decided to keep the course, and also to work to broaden its base. Historically, the design problems have been petrochemical in nature. Each team gets a reaction, with a first order rate law, as well as a production rate and fractional conversion. From this, they do the design calculations for a reactor and separator, and also generate the base engineering drawings. This past year, the project types were expanded to include environmental remediation and hydrometallurgical extraction. The environmental remediation problems involved wastewater processing (eg., BOD oxidation) which can be treated as a first order reaction. The hydrometallurgical problem (Li leaching from spodumene) also was set up as first order. Additionally, we provided the option of a case study review. The students chose a classic chemical safety incident, reviewed the details, and created a summary report which included recommendations on how to incorporate learnings from the incident into the curriculum.

Oil recovery from carbonate reservoirs is low because of their complex nature which is characterized by the presence of high permeability streaks/fractures, broad pore size distribution and oil-wet/mixed wet state. The presence of high permeability streaks/fractures causes the injected fluid to bypass the low permeability pores that contain a high percentage of producible oil. One of the most effective and promising methods to control the fluid bypass is fluid diversion using chemical agents where a chemical agent is placed in the high permeability zone to block the path for the subsequent fluid, which ultimately diverts the injected fluids to the less permeable and oil-containing region. In this work, we investigate the potential use of cellulosic nanocrystals (CNC) for fluid diversion applications. Upon contact with brine, the nanosized CNC particles agglomerate to form micron size flocs showing a viscosity increment of an order at reservoir shear rates. In our core flooding experiments, the permeability of carbonate core decreased from 2827 mD to 127 mD when a CNC dispersion of 3000 ppm was injected. Injection of pre-equilibrated de-ionized water following CNC injection showed that the permeability reduction is permanent signifying the stability of CNC agglomerates in high temperature-high salinity environments. The blocking of high permeability zones due to the agglomeration of CNC particles results in fluid diversion. This improves the sweep efficiency and allows the injected fluid to come in contact with the oil. This is the first application of CNC in the area of fluid diversion for high temperature and high salinity fractured carbonate reservoirs which are present in the Middle East.

Current practice is for pyrrhotite to be rejected from conventional nickel sulphide processing circuits due to its low concentration of nickel and high sulphur content. However, the nickel content of pyrrhotite tailings (up to 1 wt.% Ni) represents a significant resource, and a new flowsheet, based on the microwave heating of pyrrhotite tailings to produce FeNi and FeS phases is under development. The microwave heating properties of pyrrhotite tailings are explored in this paper through microwave heating and permittivity tests. Thermogravimetric analysis and differential scanning calorimetry were also performed to interpret the permittivity data, and the distribution of phases within the microwave treated material was investigated by scanning electron microscopy. In general, pyrrhotite heats very well upon exposure to microwave radiation. The mass loss appears to be governed by the sulphur content and the extent of heating seems to be influenced by the Ni content. The removal of silicate impurities by froth flotation had little impact on the heating behaviour.

The mineral processing and extractive metallurgy industries are under increasing pressure to develop more energy efficient and sustainable technologies. As a result, there is increasing interest in the application of alternative energy sources, such as microwave technology. While bench scale testing has been conducted in this area for over thirty years, scale-up has remained a key challenge. One barrier to implementation has been the lack of understanding of the fundamental interaction of microwaves with ores. Key parameters include the real and the imaginary permittivities, which influence both the heating rate and the microwave penetration depth. Over the last decade, high temperature permittivity measurements have been performed on various ores using the cavity perturbation technique. In this paper, this permittivity data is presented as a function of temperature primarily at 912 MHz. Based on the interpretation of this data, recommendations are made for the sustainable utilization of microwave technology in metallurgical processing.

Ultramafic nickel ores are difficult to process because they contain serpentine, an anisotropic mineral with a nonspherical morphology and multiple pH-dependent surface charges. Dehydroxylation of serpentine in ultramafic nickel ores by microwave treatment is proposed to improve the processability of these ores. Upon heating, serpentine is converted to olivine, an isotropic mineral that is benign in mineral processing circuits. The microwave heating of two ultramafic nickel ores is explored in this paper, as well as effects on mineralogy and grindability. The first ore was sourced from the Okanogan nickel deposit in Washington State, USA, while the second ore was obtained from the Vale-owned Pipe deposit located in the Thomson Nickel Belt in Manitoba, Canada. The ultramafic nickel ores were found to heat well upon exposure to microwave radiation and the heating behaviors were a function of the imaginary permittivities. The temperatures achieved during microwave treatment were sufficient to dehydroxylate serpentine, and the serpentine content in ultramafic nickel ores was reduced by 63&ndash, 84%. The grindability of ore with consistent texture (OK ore) improved dramatically with microwave treatment, whereas the grindability of ore with inconsistent texture (Pipe ore) was found to decrease. Pentlandite liberation and specific surface area improved for both ores with microwave treatment. Ultimately, microwave pretreatment did not decrease the energy required for grinding under the conditions studied. However, energy savings may be realized when overall process improvements are considered (e.g., grinding, rheology, flotation, material handling, dewatering and tailings treatment).

Growing demand for Li-based battery technologies is leading to an unprecedented growth in the lithium industry. Although innovation in battery technologies has pushed lithium into the spotlight, lithium was not always known for its application in batteries. The primary use of lithium—prior to the introduction of commercial lithium-ion batteries in the early 2000s—was in the ceramics, glass, grease, and the medical industry. Before being converted into usable forms, lithium products must be upgraded from the raw material. Processes for recovering lithium may involve: thermal treatment, water leaching, solar evaporation, ion exchange, carbonation, and electrodialysis. Presented, is a historical review of lithium applications and the different techniques of converting lithium-rich minerals and brines into usable products with additional discussion on future lithium extraction processes.

Mineral carbon sequestration (MCS) is a type of carbon storage based on natural rock weathering processes where CO 2 , dissolved in rainwater, reacts with alkaline minerals to form solid carbonates. Although MCS has advantages over other carbon storage techniques, an economic MCS process has not yet been developed. Two approaches were taken in this work to attempt to reduce the cost of MCS. The first approach was to use a waste material, serpentine waste from ultramafic nickel ore processing, as a feedstock. The second approach was to develop pre-treatments to increase the carbon storage capacity of the feedstock. Two pre-treatments were investigated in this work, including microwave pre-treatment and leaching with ligands at neutral to alkaline pH. The carbon uptake of ultramafic ores was found to increase with increasing microwave pre-treatment after a threshold heating time of 4 min was surpassed. A maximum carbon uptake of 18.3 g CO 2 /100 g ore (corresponding to a carbonate conversion of 36.6%) was observed for microwave pre-treated ore. The increase in carbon uptake was attributed primarily to the conversion of serpentine to olivine in ultramafic ores that occurs as result of microwave pre-treatment. The effect of five different ligands (catechol, citrate, EDTA, oxalate and tiron) on the carbon uptake of ultramafic ores was investigated. Of the ligands tested, only catechol and tiron were found to both improve the leaching of magnesium from the ores and the quantity of CO 2 stored. A maximum carbon uptake of 9.7 g/100 g ore (corresponding to a carbonate conversion of 19.3%) was observed for ultramafic ore pre-leached and carbonated in tiron solution at pH 10. This is the first time ligands have been reported to improve the carbon uptake of mineral carbon sequestration feedstock. Although process optimization work was not conducted, both microwave pre-treatment and leaching with ligands at neutral to alkaline pH show promise as ways to lower the cost of MCS.

Understanding the surface properties and interactions of nonspherical particles is of both fundamental and practical importance in the rheology of complex fluids in various engineering applications. In this work, natural chrysotile, a phyllosilicate composed of 1:1 stacked silica and brucite layers which coil into cylindrical structure, was chosen as a model rod-shaped particle. The interactions of chrysotile brucite-like basal or bilayered edge planes and a silicon nitride tip were measured using an atomic force microscope (AFM). The force-distance profiles were fitted using the classical Derjaguin-Landau-Verwey-Overbeek (DLVO) theory, which demonstrates anisotropic and pH-dependent surface charge properties of brucite-like basal plane and bilayered edge surface. The points of zero charge (PZC) of the basal and edge planes were estimated to be around pH 10-11 and 6-7, respectively. Rheology measurements of 7 vol % chrysotile (with an aspect ratio of 14.5) in 10 mM NaCl solution showed pH-dependent yield stress with a local maximum around pH 7-9, which falls between the two PZC values of the edge and basal planes of the rod particles. On the basis of the surface potentials of the edge and basal planes obtained from AFM measurements, theoretical analysis of the surface interactions of edge-edge, basal-edge, and basal-basal planes of the chrysotile rods suggests the yield stress maximum observed could be mainly attributed to the basal-edge attractions. Our results indicate that the anisotropic surface properties (e.g., charges) of chrysotile rods play an important role in the particle-particle interaction and rheological behavior, which also provides insight into the basic understanding of the colloidal interactions and rheology of nonspherical particles.

Low-grade ultramafic nickel ores, while representing a large potential nickel resource, are difficult to process due to their high serpentine content. Serpentine is anisotropic and the mineral particles tend to be non-spherical, resulting in challenging slurry rheology. In general, suspensions of serpentine minerals have high viscosity and yield stress, which can be detrimental in comminution and flotation operations. It is proposed that ultramafic nickel ores be treated with microwave radiation prior to grinding in order to reduce slurry viscosity and yield stress. The rheology of two different ultramafic nickel ores, before and after microwave pre-treatment, was characterized in this work. Serpentine minerals were found to dominate the rheology of the untreated ultramafic nickel ores, with the ore containing minor chrysotile exhibiting higher viscosity and yield stress than the ore containing strictly lizardite serpentine. Microwave pre-treatment was found to greatly reduce the shear viscosity (average 80% reduction at 200 s−1) and direct yield stress (peak yield stress reduced by 92–93%) of ultramafic nickel ore slurries. The reduction in slurry viscosity and yield stress of the ore slurries as a result of microwave pre-treatment was attributed to the conversion of serpentine to olivine.

Although mineral carbon sequestration (MCS) has several advantages over other carbon storage techniques, an economic process for MCS has not yet been developed. To reduce costs, it is suggested that MCS be combined with other processes and that waste products be used as feedstock. A process is proposed where ultramafic nickel ores are treated with microwave radiation to convert serpentine, the primary gangue mineral, to olivine. It is hypothesized the conversion of serpentine to olivine in ultramafic nickel ores may improve the mineral processing of these ores, and increase the carbon storage capacity of the flotation tailings. The microwave heating characteristics of ultramafic nickel ores, and the mineralogical changes that occur as a result of microwave treatment, are described in this paper. Ultramafic nickel ores were found to heat well in response to microwave radiation and the temperatures achieved were sufficient to convert serpentine to olivine. Microwave treatment was also found to convert pentlandite, the valuable nickel mineral, to other Fe–Ni–S minerals.

Synthetic polyester elastomeric constructs have become increasingly important for a range of healthcare applications, due to tunable soft elastic properties that mimic those of human tissues. A number of these constructs require intricate mechanical design to achieve a tunable material with controllable curing. Here, the synthesis and characterization of poly(itaconate-co-citrate-co-octanediol) (PICO) is presented, which exhibits tunable formation of elastomeric networks through radical crosslinking of itaconate in the polymer backbone of viscous polyester gels. Through variation of reaction times and monomer molar composition, materials with modulation of a wide range of elasticity (36-1476 kPa) are generated, indicating the tunability of materials to specific elastomeric constructs. This correlated with measured rapid and controllable gelation times. As a proof of principle, scaffold support for cardiac tissue patches is developed, which presents visible tissue organization and viability with appropriate elastomeric support from PICO materials. These formulations present potential application in a range of healthcare applications with requirement for elastomeric support with controllable, rapid gelation under mild conditions.

Carbon capture and storage (CCS) is gaining momentum as a means for combating climate change. It is viewed as an important bridging technology, allowing emission targets to be met during fossil fuel dependence while sufficient renewable energy generation is installed. Mineral carbon sequestration is the only known form of permanent carbon storage and has the potential to capture and store CO 2 in a single step. It is based on the geologic process of natural rock weathering where CO 2 dissolved in rain water reacts with alkaline rocks to form carbonate minerals. While the reactions are thermodynamically favourable, in nature the process occurs over thousands of years. The challenge of mineral carbon sequestration is to accelerate carbonation and exploit the heat of reaction with minimal energy and material losses. Minerals commonly selected for carbonation include calcium and magnesium silicates. These minerals require energy-intensive pre-treatments, such as fine grinding, heat treatment, and chemical activation with strong acids, to provide adequate conversions and reaction kinetics. Industrial waste residues present alternative sources of mineral alkalinity that are more reactive than primary minerals and are readily and cheaply available close to CO 2 sources. In addition, the carbonation of waste residues often improves their environmental stability. This paper provides an overview of the types of industrials wastes that can be used for mineral carbon sequestration and the process routes available.