CA2991801C - Process for producing catalysts from mining residue and catalysts produced therefrom - Google Patents

Abstract

There is provided a process for producing a catalyst from a mining residue. The mining residue can include a waste product obtained from a beneficiation plant of an ilmenite ore (FeTiO3) metallurgical complex. The process comprises obtaining a mining residue comprising hematite, alumina and magnesia; mixing the mining residue with a catalyst precursor including a catalytically active metal in order to form a mixture; milling the mixture for a period of time to form a milling product; and calcining the milling product to form the catalyst including an active metal-based spinel compound and an active metal- based solid solution. The resulting catalyst can be used for at least one of production of syngas, production of methane, hydrocarbons reforming, hydrogen production, preparation of feed gas for fuel cell units, oil refining, hydrotreatment, hydrocracking and isomerization.

Description

PROCESS FOR PRODUCING CATALYSTS FROM MINING RESIDUE
AND CATALYSTS PRODUCED THEREFROM
TECHNICAL FIELD OF THE INVENTION
[01] The technical field relates to a process for producing a catalyst from a mining residue and to the catalysts produced therefrom.
BACKGROUND

[02] Catalysts are needed in various uses to promote chemical reactions. For instance, industries related to the steam or dry reforming of hydrocarbons need catalysts for reforming water and carbon dioxide with methane to form hydrogen and carbon monoxide according to reactions (1) and (2) respectively:
(1) CH4 + H20 = 3H2 + CO
(2) CH4 + CO2 = 2H2 + 2C0 Mixed reforming using both water and carbon dioxide at various volume ratios is also a catalytic reaction. In the same category, we find also the partial oxidation (PDX) and autothermal reforming (ATR) reactions. In these cases, methane is catalytically reacting with a sub-stoichiometric quantity of oxygen to produce synthesis gas; reaction (3) represents PDX. ATR is a special case of PDX where the enthalpy of the reaction is zero.

(3) 2CH4 + 02 = 8H2 + 2C0 [03] Other examples of uses of catalysts include all types of production of syngas via other hydrocarbons reforming, hydrogen production, feed gas for fuel cell units, oil refining, hydrotreatment, hydrocracking and isomerization.

[04] Nickel-based formulations are known to be suitable catalysts for various reactions, but there are issues having regard to their efficiency, duration (life cycle) Date recue/Date Received 2018-01-09 and/or cost. There is therefore a need for more performant and cost-efficient nickel-based catalysts for at least the above-mentioned uses.

[05] Spinel-based catalysts are also known. Compounds having a spinel structure can be used as catalysts in various processes such as dehydrogenation of hydrocarbons, decomposition of alcohols, selective oxidation of carbon monoxide, hydrogen peroxide decomposition and hydrodesulfuration. Extensive literature about these uses is provided in the following publications, among others:
Gervasini, A., Auroux, A. (1990), Microcalorimetric study of the acidity and basicity of metal oxide surfaces, Journal of Physical Chemistry, 94, 6371; Gervasini, A., Auroux, A. (1991), Acidity and basicity of metal oxide surfaces II.
Determination by catalytic decomposition of isopropanol, Journal of Catalysis, 131, 190-198;
Trikalitis, P.N., Pomonis, P.J. (1995), Catalytic activity and selectivity of perovskites Lai _xSrxVi_x3+Vx4+03 for the transformation of isopropanol, Applied Catalysis A, 131, 309; Aramendia, M.A., Borau, V., Jimenez, C., Marinas, J.M., Porras, A., Urbano, F.J. (1996), Magnesium Oxides as Basic Catalysts for Organic Processes:
Study of the Dehydrogenation¨ Dehydration of 2-Propanol, Journal of Catalysis, 161, 829; Wang, J.A, Bokhimi, X., Novaro, 0., Lopez, T., Gomez, R. (1999), Effects of the surface structure and experimental parameters on the isopropanol decomposition catalyzed with sol¨gel MgO, Journal of Molecular Catalysis, 145, 291; Benrabaa, R., Boukhlouf, H., Bordes-Richard, E., Vannier, R.N, Barama, A.

(2010), Nanosized nickel ferrite catalysts for CO2 reforming of methane at low temperature: effect of preparation method and acid-base properties, Studies in Surface Science and Catalysis, 175, 301-304.

[06] It has been found that the final properties of a spinel, and therefore the catalytic characteristics of the compound formed therefrom, depend on the process by which the spinel is formed. SpineIs have been known to be formed using various processes, such as:

[07] co-precipitation (Benrabaa, R., Boukhlouf, H., Lofberg, A., Rubbens, A., Vannier, R.N, Bordes-Richard, E., Barama, A. (2012), Nickel ferrite Date recue/Date Received 2018-01-09 spinel as catalyst precursor in the dry reforming of methane: Synthesis, characterization and catalytic properties, Journal of Natural Gas Chemistry, 21, 595-604; Yang, L., Xie, Y., Zhao, H., Wu, X., Wang, Y.
(2005), Preparation and gas-sensing properties of NiFe204 semiconductor materials, Solid-State Electronics, 49, 1029-1033; Sivakum ar, P., Ramesh, R., Ramanand, A. Ponnusamy, S., Muthamizhchelvan, C.
(2011), Preparation of sheet like polycrystalline NiFe204 nanostructure with PVA matrices and their properties, Materials Letters, 65, 1438-1440);

[08] sol-gel method (Duque, J.G.S., E.A. Souzaa, E.A., Menesesa, C.T., Kubotac, L. (2007), Magnetic properties of NiFe204 nanoparticles produced by a new chemical method, Physica B, 398, 287-290; Ahmed, M.A., El-Dek, S.I., El-Kashef, I.M., Helmy, N. (2011), Structural and magnetic properties of nano-crystalline Ag+ doped NiFe204, Solid State Sciences, 13, 1176-1179);

[09] solid-state reaction (Shih, K. (2011), Phase transformation of metals in reusing the incineration ash of chemically enhanced primary treatment sludge as ceramic raw materials, Proceedings of the International Conference on Solid Waste 2011 - Moving Towards Sustainable Resource Management, Hong Kong SAR, P.R. China, 2-6 May 2011, 334-338; Marinca, T.F., Chicinas, I., Isnard, 0., Pop, V., Papa, F. (2011), Synthesis, structural and magnetic characterization of nanocrystalline nickel ferrite-NiFe204 obtained by reactive milling, Journal of Alloys and Compounds, 509, 7931-7936;
Zhang, Z., Liu, Y., Yao, G., Zu, G., Zhang, X., Ma, J. (2012), Solid-state reaction synthesis of NiFe204 nanoparticles by optimizing the synthetic conditions, Physica E, 45, 122-129.); and

[010] hydrothermal techniques (Benrabaa, R., Boukhlouf, H., Lofberg, A., Rubbens, A., Vannier, R.N, Bordes-Richard, E., Barama, A. (2012), Nickel ferrite spinel as catalyst precursor in the dry reforming of methane:
Synthesis, characterization and catalytic properties, Journal of Natural Gas Chemistry, Date recue/Date Received 2018-01-09 21, 595-604; Kiwamu, S., Muneyuki, S., Kunio, A., Tomotsugu, O., Haruo, U., Keitaro, M., Yukiya, H., Hiromichi, H., Masaru, W., Toshihiko, H. (2006), Size-controlled synthesis of metal oxide nanoparticles with a flow-through supercritical water method, Green Chemistry, 8, 634-638).

[011] However, the steps involved in each of the above-mentioned techniques for the formation of a catalytic spinet require the use of toxic organic solvents, high temperature (typically above 900 C), and long reaction time (typically above minutes). There is, therefore, a need for developing new ways to form more efficient compounds of catalytic spinel in a more cost-effective and environmentally-friendly manner.

[012] Meanwhile, available mining waste materials, or tailings, can provide a convenient source of metallic oxides such as Fe2O3, A1203 and MgO, and optionally some spinels such as MgA1204, MgFe204 and FeA1204, wherein the combination of MgFe204 and FeA1204 may be in the form of a solid solution having the formula Mg(Fe,AI)204. Such metallic oxides and spinels have the potential to be reused in various applications. A considerable amount of research has been conducted to find advantageous ways to reuse Fe203, Al2O3 and MgO tailings, since these tailings have often been regarded as zero value waste materials.
There is therefore a need for new ways to reuse mining residues comprising Fe2O3, and MgO in new applications in which their value would be increased.

[013] There is therefore a need for more performant and cost-efficient catalysts that would be formed from available mining residue.
BRIEF SUMMARY OF THE INVENTION

[014] It is therefore an aim of the present invention to address the above-mentioned issues.

[015] In accordance with an aspect, there is provided a process for producing a catalyst from a mining residue. The process comprises:

Date recue/Date Received 2018-01-09 obtaining a mining residue comprising hematite, alumina and magnesia;
mixing the mining residue with a catalyst precursor comprising an active metal, in order to form a mixture;
milling the mixture for a period of time to form a milling product; and calcining the milling product to form the catalyst including an active metal-based spinet compound and an active metal-based solid solution.

[016] In an embodiment, the mining residue comprises a metallurgical tailing.

[017] In an embodiment, the mining residue comprises at least one of an iron-based spinet compound, an aluminium-based spinet compound, and a magnesium-based spinet compound.

[018] In an embodiment, the at least one of the iron-based spinet compound, the aluminium-based spinet compound, and the magnesium-based spinet compound is at least one of MgA1204, MgFe204 and FeA1204.

[019] In an embodiment, at least one of the at least one of the iron-based spinet compound, the aluminium-based spinet compound, and the magnesium-based spinet compound is a spinet solid solution.

[020] In an embodiment, the spinet solid solution comprises Mg(Fe,AI)204.

[021] In an embodiment, the active metal is a catalytically active metal.

[022] In an embodiment, the catalytically active metal is selected from the group consisting of: nickel, cobalt, molybdenum, copper and chromium.

[023] In an embodiment, the active metal-based solid solution comprises a Mx0y-Mg0 solid solution, where M is selected from the group consisting of: nickel, cobalt, molybdenum, copper and chromium.

Date recue/Date Received 2018-01-09

[024] In an embodiment, the active metal-based solid solution comprises a NiO-Mg0 solid solution.

[025] In an embodiment, the mining residue is in the form of a micrometric powder.

[026] In an embodiment, obtaining the mining residue comprises comminuting the mining residue into a micrometric powder.

[027] In an embodiment, the micrometric powder includes particles characterized by a size comprised between about 1 pm and about 100 pm.

[028] In an embodiment, obtaining the mining residue comprises adding a binding agent to the micrometric powder, mixing the binding agent and the micrometric powder, and pelletizing the mixture to produce millimetric sized pellets.

[029] In an embodiment, mixing the mining residue comprises adding the catalyst precursor in an amount corresponding substantially to a stoichiometry of reactions forming the milling product.

[030] In an embodiment, mixing the mining residue comprises adding the catalyst precursor in an amount in excess or deficient with respect to a stoichiometry of reactions forming the milling product.

[031] In an embodiment, the catalyst precursor is added in a stoichiometric mole ratio of 0.5 to 1.5 with reactions forming the milling product.

[032] In an embodiment, mixing the mining residue comprises adding at least one of water and acetone with the catalyst precursor.

[033] In an embodiment, the catalyst precursor comprises at least one of nickel, cobalt, molybdenum, copper and chromium.

[034] In an embodiment, the catalyst precursor comprises at least one of a nitrate, a sulfite, and a chloride.

Date recue/Date Received 2018-01-09

[035] In an embodiment, the catalyst precursor is a hydrated precursor.

[036] In an embodiment, the catalyst precursor is an inorganic or organic nickel salt.

[037] In an embodiment, the catalyst precursor comprises nickel nitrate hexahydrate (Ni(NO3)2.61-120).

[038] In an embodiment, the nickel nitrate hexahydrate is added in an amount corresponding to a stoichiometry of reactions forming NiFe204 and NiA1204.

[039] In an embodiment, the nickel nitrate hexahydrate is added in an amount in excess with respect to a stoichiometry of reactions forming NiFe204 and NiA1204.

[040] In an embodiment, the catalyst precursor comprises nickel chloride (NiCl2).

[041] In an embodiment, the catalyst precursor comprises hexahydrated nickel chloride (NiC12.6H20).

[042] In an embodiment, the process further comprises drying the milling product to obtain a dry milling product and wherein calcining the milling product comprises calcining the dried milling product.

[043] In an embodiment, drying the milling product is carried out at a drying temperature comprised between about 75 C and about 130 C.

[044] In an embodiment, milling the mixture is carried out for a milling time period comprised between about 2 and about 10 minutes.

[045] In an embodiment, calcining the milling product is carried out for a calcining time period comprised between about 1 and about 12 hours.

[046] In an embodiment, calcining the milling product is carried out at a calcining temperature comprised between about 850 C and about 1100 C.

Date recue/Date Received 2018-01-09

[047] In an embodiment, the calcining temperature is comprised between about 900 C and about 950 C.

[048] In an embodiment, the mining residue comprises a waste product obtained from a beneficiation plant of an ilmenite ore (FeTiO3) metallurgical complex.

[049] In an embodiment, the process further comprises regenerating the catalyst by subjecting the catalyst to a further calcining.

[050] In accordance with another aspect, there is provided the catalyst obtained by the process as described herein.

[051] In accordance with another aspect, there is provided a use of a catalyst obtained from the process as described herein for at least one of production of syngas, production of methane, hydrocarbons reforming, hydrogen production, preparation of feed gas for fuel cell units, oil refining, hydrotreatment, hydrocracking and isomerization.

[052] In accordance with another aspect, there is provided a process for at least one of production of methane, hydrocarbons reforming, hydrogen production, preparation of feed gas for fuel cell units, oil refining, hydrotreatment, hydrocracking and isomerization using a catalyst obtained from the process as described herein.

[053] In accordance with another aspect, there is provided a catalyst for use in at least one of production of syngas, production of methane, hydrocarbons reforming, hydrogen production, preparation of feed gas for fuel cell units, oil refining, hydrotreatment, hydrocracking and isomerization. The catalyst comprises an active metal-based spinel compound and an active metal-based solid solution originating from a solid-state reaction between a catalyst precursor, comprising a catalytically active metal, and a mining residue comprising hematite, alumina, and magnesia.

[054] In an embodiment, the catalytically active metal is selected from the group consisting of: cobalt, molybdenum, copper, chromium, and nickel.

Date recue/Date Received 2018-01-09

[055] In an embodiment, the catalytically active metal comprises nickel.

[056] In an embodiment, the active metal-based solid solution comprises a NiO-MgO solid solution.

[057] In an embodiment, the mining residue comprises a metallurgical tailing.

[058] In an embodiment, the mining residue comprises a waste product obtained from a beneficiation plant of an ilmenite ore (FeTiO3) metallurgical complex.

[059] In an embodiment, the mining residue comprises at least one of an iron-based spinel compound, an aluminium-based spinel compound, and a magnesium-based spine! compound.

[060] In an embodiment, the at least one of the iron-based spinel compound, the aluminium-based spinel compound, and the magnesium-based spinel compound is at least one of MgA1204, MgFe204 and FeA1204-

[061] In an embodiment, at least one of the at least one of the iron-based spinel compound, the aluminium-based spinel compound, and the magnesium-based spinel compound is a spinel solid solution.

[062] In an embodiment, the spinet solid solution comprises Mg(Fe,AI)204 and at least one of the nickel based spinel.

[063] In an embodiment, the mining residue is in the form of a micrometric powder including particles characterized by a size comprised between about 1 pm and about 100 pm.

[064] In an embodiment, the catalyst precursor is present in an amount corresponding substantially to a stoichiometry of reactions forming the catalyst.

[065] In an embodiment, the catalyst precursor is present in a stoichiometric mole ratio of 0.5 to 1.5 with reactions forming the catalyst.

Date recue/Date Received 2018-01-09

[066] In an embodiment, the catalytically active metal comprises at least one of nickel, cobalt, molybdenum, copper and chromium.

[067] In an embodiment, the catalytically active metal comprises at least one of a nitrate, a sulfite, and a chloride.
[067a] In accordance with another aspect, there is provided a process for producing a catalyst from a mining residue, comprising: obtaining the mining residue comprising hematite, alumina and magnesia; mixing the mining residue with a catalyst precursor comprising a catalytically active metal, in order to form a mixture;
milling the mixture for a period of time to form a milling product; and calcining the milling product to form the catalyst including an active metal-based spinel compound and an active metal-based solid solution.
[067b] In accordance with another aspect, there is provided a process for producing a catalyst from a mining residue, comprising: obtaining the mining residue comprising hematite, alumina and magnesia, wherein a combination of the hematite, alumina and magnesia represents more than 50 wt% of the mining residue; mixing the mining residue with a catalyst precursor comprising a catalytically active metal, in order to form a mixture; milling the mixture for a period of time to form a milling product; and calcining the milling product to form the catalyst including an active metal-based spinel compound and an active metal-based solid solution.
[067c] In accordance with another aspect, there is provided a catalyst for use in at least one of production of syngas, production of methane, hydrocarbons reforming, hydrogen production, preparation of feed gas for fuel cell units, oil refining, hydrotreatment, hydrocracking and isomerization, comprising an active metal-based spinel compound and an active metal-based solid solution originating from a solid-state reaction between a catalyst precursor, comprising a catalytically active metal, and a mining residue comprising hematite, alumina, and magnesia, wherein a combination of the hematite, alumina and magnesia represents more than 50 wt%
of the mining residue.

Date Recue/Date Received 2022-05-26 BRIEF DESCRIPTION OF THE FIGURES

[068] Fig. 1 is a flowchart of a process for producing a catalyst from a mining residue, in accordance with an embodiment.

[069] Fig. 2 is a plot showing the conversion of methane, and hydrogen yield over time in a dry reforming reaction carried in presence of two different catalysts and a UGSO tailing.

[070] Fig. 3A is a plot showing the conversion of methane, and hydrogen yield over time in a dry reforming reaction for a Ni-UGSO catalyst produced with a first batch of starting material.

[071] Fig. 3B is a plot showing the conversion of methane, and hydrogen yield over time in a dry reforming reaction using a catalyst produced with a second batch of starting material (13_A.S_2).

[072] Fig. 4 presents XRD spectra of a UGSO tailing before and after test.

[073] Fig. 5 presents XRD spectra of the Ni-UGSO catalyst before and after test.

[074] Fig. 6 presents XRD spectrum of the Ni-UGSO catalyst that has been used for 4 hours as a catalyst in a dry reforming reaction and of the same catalyst following regeneration.

[075] Fig. 7 presents XRD spectrum of the Ni-UGSO catalyst that has been used for 7 days as a catalyst in a dry reforming reaction and of the same catalyst following regeneration.
- 10a -Date Recue/Date Received 2022-05-26

[076] Fig. 8A presents a micrograph obtained by Scanning Electron Microscopy (SEM) of the UGSO tailing before test.

[077] Fig. 8B presents a SEM micrograph of the Ni-UGSO catalyst before test.

[078] Fig. 8C presents a SEM micrograph of the UGSO tailing after test, wherein the test consisted of 4 hours of dry reforming reaction with a CO2/CH4 mole ratio of 1.

[079] Fig. 8D presents a SEM micrograph of the Ni-UGSO catalyst after test, wherein the test consisted of 4 hours of dry reforming reaction with a CO2/CH4 mole ratio of 1.

[080] Fig. 8E presents a SEM micrograph of the Ni-UGSO catalyst after test, wherein the test consisted of 7 days of dry reforming reaction with a CO2/CH4 mole ratio of 1.6.

[081] Fig. 9A presents an EDX spectrum of the UGSO tailing of Fig. 8A.

[082] Fig. 9B presents an EDX spectrum of the Ni-UGSO catalyst of Fig. 8B.

[083] Fig. 9C presents an EDX spectrum of the UGSO tailing of Fig. 8C.

[084] Fig. 9D presents an EDX spectrum of the Ni-UGSO catalyst of Fig. 80.

[085] Fig. 9E presents an EDX spectrum of the Ni-UGSO catalyst of Fig. 8E.

[086] Fig. 10 presents XRD spectra of two samples of Ni-UGSO catalyst that have been produced in different batches, using the process described in Fig. 1.

[087] Fig. 11 is a plot showing the fraction of conversion of methane in a mixed reforming reaction at different temperatures, wherein the catalyst (13_A.S_2) of Figure 3B is used as a catalyst.

[088] Fig. 12 presents XRD spectra of the two batches of Ni-UGSO catalyst of Figure 10, after having been used as catalysts for 4 hours and 74 hours Date recue/Date Received 2018-01-09

[089] Fig. 13 compares XRD spectra of three samples of Ni-UGSO catalyst, i.e.
13_S.S (5) (B.T.), 13_ S.S. (2.5) (B.T.) and 13_A.S_2 (B.T.).

[090] Fig. 14 is a plot showing the conversion of CH4 for a mixed reforming reaction of 4 hours using the samples of Fig. 13 as catalyst

[091] Fig. 15 is a plot showing H2 yield for the reaction of conversion of CH4 conducted for 4 hours using the samples of Fig. 13 as catalyst.

[092] Fig. 16 is a plot showing CO yield for the reaction of conversion of CH4 conducted for 4 hours using the samples of Fig. 13 as catalyst.

[093] Fig. 17 compares XRD spectra of the three samples of Ni-UGSO catalyst of Fig. 13, after the reaction of conversion of CH4 has been conducted for 4 hours.

[094] Fig. 18 is a plot showing methane conversion and hydrogen yield over time in a steam reaction using a catalyst produced with a third batch of starting material (3rd batch).

[095] Fig. 19 is a plot showing a ratio H2/C0 over time in a steam reaction using the catalyst produced with the third batch of starting material (3rd batch).

[096] It will be noted that throughout the appended drawings, like features are identified by like reference numerals.
DETAILED DESCRIPTION

[097] In reference to the accompanying drawings, a process for forming a catalytic compound from a mining residue using a solid-state reaction will be described.
It is contemplated that the catalytic compound can be used in a variety of applications.
For instance and without being limited to the following list, the catalytic compound is contemplated to be used in the production of syngas, methane and other hydrocarbons reforming, hydrogen production, feed gas for fuel cell units, oil Date recue/Date Received 2018-01-09 refining, hydrotreatment, hydrocracking, isomerization or in any other use wherein efficient and/or cost-effective catalytic compounds are suitable.

[098] As it will be better understood in view of the following description and referring to Fig. 1, there is provided a process (100) for producing a catalyst from a mining residue. The term "mining residue" is intended to mean a waste product of the mining/metallurgical industry and includes metallurgical tailings, i.e. a waste product from a metallurgical plant (process). In an embodiment, the mining residue is a waste product obtained in a beneficiation plant of an ilmenite ore (FeTiO3) metallurgical complex. For instance, the mining residue comprises or is an ilmenite tailing. It is to be noted that, in Fig. 1, the steps mentioned in a dotted-line box are optional and are only presented in an exemplary order. In the following description, the mining residue can be referred to as a residue. The terms residue and tailing are considered similar and are sometimes used interchangeably throughout the description. Generally, and as it will be described below, the resulting catalyst produced by the process (100) comprises a plurality of spinel compounds suitable for various applications, such as acting as a catalyst in a reaction of reforming of hydrocarbons.

[099] In an embodiment, the first step of the process (100) involves obtaining a mining residue (110). The residue includes hematite (Fe2O3), alumina (A1203), and magnesia (MgO), i.e. iron, aluminium, and magnesium oxides. In an embodiment, the residue comprises the metallic oxides hematite (Fe2O3), alumina (A1203) and magnesia (MgO) and other constituents (mainly oxides). In an embodiment, the mining residue comprises at least one of an iron-based spinel compound, an aluminium-based spinel compound, and a magnesium-based spinel compound. In another embodiment, at least one of the at least one of the iron-based spinel compound, the aluminium-based spinel compound, and the magnesium-based spinel compound, present in the residue, is a spinel solid solution. The residue can include a waste product obtained from a beneficiation plant of an ilmenite ore (FeTiO3) metallurgical complex. In an embodiment, the main constituent of the Date recue/Date Received 2018-01-09 mining residue is or includes an iron oxide, such as hematite. In an embodiment, the residue comes from a UGSTM (upgraded slag) processing unit from a plant operated by Rio Tinto Fer & Titane located in Sorel-Tracy, Canada. This residue will be referred to as the UGS Oxide (UGSO) residue hereinafter.

[0100]The UGSO residue is provided in the form of fine beads ranging in size from a few centimeters to micrometers. The UGSO residue is cost efficient, since it is a waste product and no further fragmentation (crushing or grinding) or complex treatment is required prior to the following process (100).

[0101]COREM, an independent laboratory, was given a sample of the UGSO
residue for conducting chemical analyses. The concentrations of metallic oxides found in the sample of the UGSO residue sample are provided in Table 1.
Table 1: Concentration of metallic oxides found in the UGSO residue sample Compound %w Fe2O3 44.7 MgO 29.0 A1203 10.1 CaO 1.5 MnO 1.3 V205 1.6 TiO2 1.0 SiO2 0.18 Na2O 0.23 K20 0.03 P205 0.02 Cr2O3 0.74 ZrO2 0.02 ZnO 0.01

[0102]It is to be understood that other chemical compositions of the UGSO
residue are to be contemplated depending on the metallurgical process from which the UGSO residue originates. However, the UGSO residue is to be understood as being composed of hematite, magnesia and alumina as the main constituents (i.e.
above 50 wt%), and of other constituents. In an embodiment, the UGSO residue includes 75 wt.-% or more of a combination of hematite, magnesia and alumina.
In Date recue/Date Received 2018-01-09 another embodiment, the UGSO residue includes 80 wt.-% or more of a combination of hematite, magnesia and alumina.

[0103] In an embodiment, the next step involves comminuting, such as by milling, the UGSO residue in order to obtain a micrometric UGSO residue powder (120).
For example and without being limited to, the comminution step (120) can be conducted with a mortar at lab scale. At industrial scale, the comminution step (120) can be performed by ball milling or using hammer mills or any suitable method capable of producing the desired particle size distribution.
Optionally, a sieve can be used to separate the micrometric powder in order to isolate the particles having a size between 1 and 100 pm. In an embodiment, a sieve can be used to isolate the particles having a size below about 53 pm. It is to be understood that other particles sizes can be isolated to obtain a resulting substantially micrometric powder. In an embodiment, a binding agent is added to and mixed with the micrometric powder of mining residue, and the mixture is pelletized to produce millimetric sized pellets.

[0104]The next step involves mixing the micrometric UGSO residue powder with a catalyst precursor in order to form a mixture (130). In an embodiment, the mixing step (130) can be performed while the UGSO residue undergoes the comminution step (120) described above.

[0105]The catalyst precursor is the constituent providing the necessary species required to form the spinel compound(s), solid solution(s) or a combination thereof.
The catalyst precursor includes a catalytically active metal to promote a chemical reaction. In some implementations, the catalyst precursor includes nickel, cobalt, molybdenum, copper and/or chromium as active metal(s). In some implementations, the catalyst precursor can be a hydrated compound. In some implementations, the catalyst precursor includes a nitrate, a chloride or a sulfite. In some implementations, the catalyst precursor includes nickel and, more particularly, any nickel compound which can give NiO after calcining. In an embodiment, the nickel compound can be an inorganic or organic nickel salt. In an Date recue/Date Received 2018-01-09 embodiment wherein the catalyst precursor is H20 free, water or any other suitable solvent can be added along with the catalyst precursor in order to form a mixture.
In some implementations, the catalyst precursor can be added in an amount selected to respect the stoichiometry of a given reaction to obtain a milling product and/or the catalyst, or in other proportions with respect to the stoichiometry of a given reaction to obtain the milling product and/or the catalyst.

[0106]1n a particular embodiment, the catalyst precursor is nickel nitrate hexahydrate (Ni(NO3)2.6H20). In other implementations, the catalyst precursor can be nickel chloride (NiCl2) or hexahydrated nickel chloride (NiC12.6H20) or any suitable nickel compound allowing to obtain NiO after calcining. In some of the examples detailed below, a nickel nitrate hexahydrate, 98% pure and manufactured by Alfa AesarTM, was used as catalyst precursor. In an embodiment wherein the catalyst precursor is nickel nitrate hexahydrate, the catalyst precursor can be added in an amount selected to respect the stoichiometry of the following reactions (4) and (5) :
(4) Ni(NO3)2.6H20 + Fe2O3 + 1/202 (calcining) = NiFe204 + 2NO3 + 6H20 (5) Ni(NO3)2.6H20 + Al2O3 + 1/202 (calcining) = NiA1204 + 2NO3 + 6H20 [01011t is to be noted that reactions (4) and (5) are incomplete since there can also be decomposition of NO, NOx, etc.
[0108] In another embodiment, the catalyst precursor can be added to be in excess or deficient with respect to the stoichiometry of the reactions (4) and (5).
For instance and without being limitative, the catalyst precursor can be added in a stoichiometric mole ratio of about 0.5 to about 1.5 with respect to the milling product.
[0109] Optionally, during this step (130), acetone, or any other suitable solvent, can be added to the mixture in order to drench the mixture, thus forming agglomeration of particles of the mixture. In some implementations, the mixture is drenched with a Date recue/Date Received 2018-01-09 minimal amount of acetone. For example, 1 to 3 ml of acetone can be added for each 10g of mixture. In some implementations, other solvents, such as water and alcohols, can be used as well.
[0110p-hen, the following step involves milling the mixture (140). The milling step (140) can be conducted for up to 30 minutes. In an embodiment, the mixture is milled between about 2 and about 10 minutes. In some implementations, the milling step (140) can be conducted using a mortar or a ball mill.
[01111During the milling of the mixture (140), the catalyst precursor is intimately mixed with the UGSO residue. In an embodiment, the liberation of the water bonded to the nickel nitrate hexahydrate allows an intimate mixture of the two reactants, thus allowing a plurality of solid-state reactions to occur.
Reactions (4) and (5) are only exemplary reactions of a variety of solid-state reactions that can occur when the catalyst precursor of nickel nitrate hexahydrate and the UGSO
residue are mixed. Optionally, at the end of the milling step (140), acetone or water can be added in the same proportion as described above to further homogenize the milling product.
[0112]The next step involves drying the resulting milling product to form a dry mixture (150). This drying step (150) can involve, for instance, placing the milling product into an oven where it can be spread or distributed to dry evenly. In an embodiment, the milling product can be dried at a temperature comprised between about 75 C and about 130 C. In an embodiment, the milling product is dried at a temperature comprised between about 100 C and about 110 C. In some implementations, the milling product can be dried for 5 to 12 hours. An objective of this drying step (150) is to evaporate the water liberated or added during the previous milling step (140) from the milling product in order to form a dry milling product. Another objective is to evaporate the acetone, or any other solvent, that could be present in the milling product in some scenarios. Other suitable drying time and temperatures can be selected according to various factors, such as the size of particles in the dry milling product, or the water and/or acetone content of Date recue/Date Received 2018-01-09 the milling product. In an industrial production scenario, this drying step (150) can be conducted using industrial scale solid driers including, but not limited by, batch or continuous tray or tunnel or fluid bed units.
[0113]The final step of the process involves calcining the dry milling product (160).
This calcining step (160) can involve, in an embodiment, placing the dry milling product into a kiln, an oven or any other suitable industrial furnace capable of reaching temperatures as high as 1200 C, typically. In some implementations, the calcining step is conducted for a period of time comprised between 1 and 12 hours at a temperature comprised between about 850 C and about 1100 C. Other suitable calcining time and temperatures can be contemplated according to various factors, such as the size of particles in the dry milling product, or the spinel compounds that are aimed to be formed. In some scenarios, the calcining temperature is comprised between 900 C and 950 C. Reactions (4) and (5) are only exemplary reactions of a variety of solid-state reactions that can occur when the catalyst precursor of nickel nitrate hexahydrate and the UGSO residue are mixed.
[0114]After the calcining step (160), the resulting calcined powder is referred to as a catalyst. In an embodiment, the resulting catalyst may include (a) the catalytically active metal in the form of oxide, spinels, oxides solutions or spinel solutions; (b) at least iron, aluminum and magnesium oxides; (c) at least one of iron, aluminium, and magnesium-based spinel compounds and (d) at least one of iron, aluminium, and magnesium-based solid solution.
[01151In an embodiment, the catalyst powder can further be screened in order to get a powder with particles below about 53 pm in size, or any other desirable particle size. In an embodiment, the powder can be converted to any other suitable form such as and without being !imitative, a catalyst-impregnated monolith, pellets, pills, etc. with or without additional step(s).

Date recue/Date Received 2018-01-09 [0116]It will be appreciated that the methods and processes described herein may be performed in the described order, or in any suitable order. In an embodiment, some steps can be omitted. For instance, the comminution and/or drying steps (120, 150) can be omitted. In an embodiment, the use of a solvent can be omitted if the mining residue and/or the catalyst precursor includes a minimal amount of free water, which is estimated to be around 20% w/w.
[0117]The above-described process (100) presents various advantages compared to other known techniques mentioned above for forming spine] compounds. For instance, the process (100) is expected to be cost effective since it requires less time and less organic solvent than other known techniques. In an embodiment, the process (100) is expected to not require any solvent, such as acetone, for agglomerating or drenching the powder. In addition, the milling, drying and calcining steps (140, 150, 160) described above are expected to be cost effective compared to the steps required in the other known techniques.
[0118]In the embodiment wherein the active metal of the catalyst precursor includes nickel, the final product is therefore a catalyst composed of iron, aluminium, magnesium-based spinel compounds including, and not limited to, NiFe204, NiA1204, MgFe204, MgA1204, FeNiA104 and/or Mg(FeA1)204 as a solid solution, and/or a solid solution of NiO and MgO. In an embodiment, the active metal-based solid solution comprises a MO-MgO solid solution, where M is selected from the group consisting of nickel, cobalt, molybdenum, copper and chromium. In a particular embodiment, the active metal-based solid solution is a NiO-MgO solid solution. The final product, hereinafter referred to as a Ni-UGSO
catalyst, can be used as a catalyst powder for the promotion of various reactions.
More details regarding the composition of the Ni-UGSO catalyst are provided below. It is appreciated that the composition of the catalyst varies in accordance with the active metal(s) used as catalyst precursor and the content of the mining residue.

Date recue/Date Received 2018-01-09 [0119]At the end of the process described above, the Ni-UGSO catalyst is ready for use, which can be advantageous for end users of the Ni-UGSO catalyst.
Moreover, if the Ni-UGSO catalyst becomes deactivated over time by mechanisms known in the art, the catalytic properties of the Ni-UGSO catalyst can be regenerated. For instance, the catalytic properties of the Ni-UGSO catalyst can be regenerated by subjecting the Ni-UGSO catalyst to a subsequent calcining step, for instance, similar to the calcining step (160) of the process (100) described above.
More details about the regeneration of the Ni-UGSO catalyst are provided below.
[0120]As mentioned above, the Ni-UGSO catalyst can present various advantages related to production costs. Moreover, the Ni-UGSO catalyst showed advantageous catalytic properties over other known catalysts.
[0121]It appears that the different spinel compounds and/or constituents comprised in the Ni-UGSO catalyst have a synergistic effect and provide advantageous catalytic properties to the Ni-UGSO catalyst. For instance, the results showed that the MgO itself and its compounds can act as a support and/or a moderator, thereby preventing or minimizing the deposition of carbon on the catalytic compound; said deposition of carbon ultimately leads to the deactivation of the catalyst compound.
[0122]In order to demonstrate the advantageous catalytic properties of the Ni-UGSO catalyst, the following comparative examples are provided.
[0123]Example 1: Preparation of a Ni-UGSO catalyst for the purpose of comparison with the UGS0 residue and the NiFe204 catalysts in a reaction of dry reforming of hydrocarbon [01241 In the following example, the performances of a Ni-UGSO catalyst produced in accordance with the process described herein was compared to a catalyst prepared with a similar process, but using a different reactant. The comparison between the two catalysts compares the performances of each catalyst in a reaction of dry and mixed reforming of hydrocarbon.

Date recue/Date Received 2018-01-09 [0125]In particular, instead of first providing a mining residue such as the UGSO
residue as the main reactant, an almost pure nanometric Fe2O3 powder was provided. Thus, contrary to the UGSO residue, there is no significant amount or proportion of alumina or magnesia in this reactant. For this example, the Fe2O3 powder that was used is a commercially available powder traded under the name NanocatTM Ultrafine iron oxide, 4nm.
[0126]First, the Fe2O3 powder was drenched with acetone in order to agglomerate the nanometric particles into micrometric particles. The acetone used was a commercially available laboratory grade acetone. The resulting micrometric powder was then dried in an oven at about 80 C to evaporate the acetone.
[0127]The micrometric powder was then mixed with nickel nitrate hexahydrate (Ni(NO3)2.6H20) in a concentration of 13% w/w, and milled using a mortar for 10 to 15 minutes. As described above, the liberation of the water bonded to the nickel nitrate allowed an intimate mixture of the two reactants, allowing the solid-state reaction to occur during which the spine! compound NiFe204 was formed, in accordance with reaction (4) above. At the end of the milling step, a low quantity of acetone (3 ml of acetone for each 10g of mixture) was added to further homogenize the mixture.
[0128]The resulting milling product was then dried in an oven at a temperature of 105 C for 5 to 10 hours, thus forming the dry milling product.
[0129]The dry milling product was then calcined for about 12 hours at a temperature of about 900 C.
[0130]After the calcining step, the resulting calcined powder was screened in order to get a powder with particles below 53 pm in size. The resulting calcined powder will be referred to as the NiFe204 catalyst hereinafter.
[0131]The Ni-UGSO catalyst was prepared in accordance with the same parameters as described above for the NiFe204 catalyst, except that the starting Date recue/Date Received 2018-01-09 reactant, i.e. the UGSO residue, was already provided in micrometric powder form.
Thus, the comminution and drying steps described above were omitted.
(0132] For practical reasons, the comparison of the performances of the Ni-UGSO
and the NiFe204 catalysts involves using them as a catalyst in a reaction of dry reforming of methane (CH4) with a stoichiometric mole ratio CO2/CH4 = 1.
[0133]Various experiments and comparison between the catalysts will now be described. For the purpose of this experimentation, a sample of as-received UGSO
residue, i.e. non-calcined and free of Ni as catalyst precursor, was also tested in order to assess its catalytic properties. Thus, the catalysts that were tested were the UGSO residue, the NiFe204 catalyst and the Ni-UGSO catalyst.
[0134]Referring to Fig. 2, there is provided a plot comparing the fraction of conversion of CH4 and yield of H2 over time for each catalyst. It will be described below that the synergistic effects of the various spinel compounds found in the Ni-UGSO catalyst have an impact on its performances compared to the other catalysts. In particular, the NiO-MgO solid solution has the potential to catalyse the reforming reaction, and also to avoid carbon formation due to the basic character of MgO.
(0135] Having regard to the test involving the NiFe204 catalyst, the reaction of dry reforming of methane (CH4) was conducted with 0.3g of NiFe204 catalyst at 810 C
for 4 hours with a stoichiometric mole ratio CO2/CH4 = 1. Fig. 2 shows that the conversion of methane reached 39% after 30 minutes before reaching 25% after 4 hours of reaction. This corresponds to a deactivation of the catalyst of 36%
after 3 hours of reaction time. The same trend was observed for the H2 yield, passing from 50% after 1 hour of reaction time to 30% after 4 hours. The experimental conditions were the same for all of the following tests.
(0136] For the purpose of this experimentation, the UGSO residue was only milled to micrometric size and used as a catalyst. Again, the reaction of dry reforming of methane (CH4) was conducted in the same conditions as described above with Date recue/Date Received 2018-01-09 0.3g of UGSO residue powder at 810 C for 4 hours with a stoichiometric mole ratio CO2/CH4 = 1. Fig. 2 shows that the conversion of methane reached 18% after 4 hours of reaction. The H2 yield has passed from 40% after 30 minutes of reaction to 22% after 4 hours.
[0137]Finally, the Ni-UGSO catalyst was tested. Once again, the reaction of dry reforming of methane (CH4) was conducted with 0.3g of Ni-UGSO catalyst at 810 C for 4 hours with a stoichiometric mole ratio CO2/CH4 = 1. Fig. 2 shows that the conversion of methane reached 87% while remaining stable for the 4 hours of the reaction time. The same trend was observed for the H2 yield, being stable for the 4 hours of the reaction time at about 81%.
[0138] It is apparent from the results shown in Fig. 2 that the synergistic effect of the plurality of the constituents of the Ni-UGSO catalyst provides advantageous performances to the Ni-UGSO catalyst when used as a catalyst in a reaction of dry reforming of methane, compared to the NiFe204 catalyst and to the UGSO
residue, in the same conditions.
[0139]Example 2: Assessment of the stability of the Ni-UGSO catalyst on dry reform inq of methane [0140]Referring to Fig. 3A, the long term stability of the Ni-UGSO catalyst has been assessed during a reaction of dry reforming of methane (CH4) with a stoichiometric mole ratio CO2/CH4 = 1.6, at 810 C. The reaction was conducted over 7 days and 0.3 g of Ni-UGSO catalyst was used. The results show that the loss of activity of the Ni-UGSO catalyst was the greatest during the first day (-11%
of conversion of CH4 and -10% in H2 yield) before stabilizing at an average of -1.3% of conversion of CH4 and -0.7% in H2 yield, per day. It is to be noted that, with a mole ratio of CO2/CH4 = 1.6, the effect of a Reverse Water Gas Shift is non-negligible in this reaction.
[0141]Fig. 3B presents another assessment of the stability of the Ni-UGSO
catalyst with respect to a dry reforming reaction of methane. A second Ni-UGSO

Date recue/Date Received 2018-01-09 catalyst batch (encoded as 13_A.S_2, A.S referring to with solvenb) was prepared for this experiment. The second batch of catalyst has been prepared using the same process (100) as described above, wherein the parameters were:
13%-w/w of Ni; 3 ml of solvent (acetone) for 10g of catalyst; and 5 minutes of milling. The stability assessment experiment has been carried out for 7 days at 840 C and with a stoichiometric mole ratio CO2/CH4 = 1.2. The loss of activity of the sample of the second batch of Ni-UGSO catalyst was the greatest during the three days (-6% of conversion of CH4) before stabilizing and having a loss of activity of only -1% over the four following days. The results, shown in Fig.
3B, have been compared with those presented in Fig. 3A. These results confirm that the sample of the second batch of Ni-UGSO catalyst, i.e. 13_A.S_2, was stable during the experiment, thus demonstrating the reproducibility of the process (100).
(0142] Referring to Figs. 4 to 7, spectra of X-ray diffraction (XRD) analyses of the UGSO residue and of the Ni-UGSO catalysts are presented. The analyses were conducted before and after the above mentioned tests. In the following Figs. 4 to 17, abbreviations "B.T." and "A.T." stand for "before test" and "after test", respectively.
[0143]Referring to Fig. 4, the analysis after test of the UGSO residue presents peaks specific to MgO, FeO and (MgFe)0 and an important decrease of the initial spinel phases (AlFe204, MgA1204, MgFe204, MgFeA104) that were found in the sample before test.
[0144]Referring to Fig. 5, the same phenomenon is observed for the Ni-UGSO
catalyst, but the analysis also shows the appearance of metallic Ni and of some alloys such as FeNi, FeNi3, NiAl and FeNiAl. However, the NiFe204 spinel compound disappear in the analysis conducted after tests. It is believed that the presence of hydrogen generated during the dry reforming reaction leads to the reduction of NiFe204 spinel compound into FeO, NiO and metallic Ni, Fe and of some other alloys such as FeNi, FeNi3 and Fe3Ni2.

Date recue/Date Received 2018-01-09 [0145]Contrary to the spinet compound NiA1204 which is more stable at the conditions of the dry reforming reaction, other spinet compounds that are constituents of the UGSO residue and the Ni-UGSO catalyst, along with pure NiFe204 spinel compound, have been converted due to in situ reduction reactions.
However, even with these reduction reactions going on, the Ni-UGSO catalyst remains substantially active and, when its activity drops below an acceptable level (typically lower than 85% of its initial activity), it can be regenerated by means of the process described below.
[0146]Example 3: Regeneration of Ni-UGSO catalyst [0147]Regeneration experiments have been conducted on the Ni-UGSO catalyst.
A Ni-UGSO catalyst that has been subjected to the previously described tests was then further calcined at 900 C for 12 hours under atmospheric air. These conditions correspond to the calcining step (160) described above.
[0148]Referring to Figs. 6 and 7, XRD spectra of a "used" (A.T.) and of a "regenerated" (A.T. Cal.) Ni-UGSO catalyst are presented and compared to the Ni-UGSO catalyst before test (i.e. before acting as a catalyst in the dry reforming reaction). Fig. 6 presents the spectrum of a Ni-UGSO catalyst that has been used for 4 hours as a catalyst in the dry reforming reaction, while Fig. 7 presents the spectrum of a Ni-UGSO catalyst that has been used for 7 days. The stoichiometric mole ratio of CO2/CH4 during the dry reforming reaction was 0.98 for the 4 hour dry reforming reaction and 1.6 for the 7 day dry reforming reaction.
[0149]The XRD spectra of Figs. 6 and 7 show that the regeneration due to a further step of calcining regenerated the initial structure of the Ni-UGSO
catalyst, i.e. the spectrum of the Ni-UGSO A.T. Cal. sample substantially correspond to the spectrum of the Ni-UGSO B.T. sample, for both samples having been subjected to reaction time of 4 hours and 7 days, respectively. Therefore, it is contemplated that this regeneration procedure can be repeated several times, thereby extending the useful lifespan of the Ni-UGSO catalyst.

Date recue/Date Received 2018-01-09 [0150]Referring to Figs. 8A to 8E, different micrographs, obtained with a scanning electron microscope (SEM), show the evolution of the morphology of the UGSO
and Ni-UGSO catalysts powder B.T. and A.T. These SEM micrographs show that there is some sintering occurring due to the high temperatures involved during the dry reforming reaction. This sintering of the catalyst powders leads to a certain coalescence or agglomeration of the particles. These phenomena can explain the decrease of the fractional conversion of CH4 and of the H2 yield, since there is a decrease of the active surface area of the catalyst over time. However, it can be noted from these images that there is no accumulation of carbon in both the UGSO
tailing and the Ni-UGSO catalysts after tests (A.T.).
[0151]Further energy dispersive X-ray ([DX) analyses were conducted using the scanning electron microscope [DX module. Figs. 9A to 9E present qualitative analyses of the elements composing the UGSO and Ni-UGSO catalysts. It can be noted, with the arrow at the left end of each spectrum, that the carbon peak appears to be similar in catalysts both before test and after test, suggesting that the catalysts do not accumulate carbon. These analyses also suggest that the decrease of the activity of the catalysts is due essentially to the decomposition of the spinel compounds of the catalysts.
[0152]Example 4: Assessment of the reproducibility of the process for forminq Ni-UGSO catalyst [0153]Referring to Fig. 10, the reproducibility of the process (100) has been assessed. The same second batch of Ni-UGSO catalyst that has been prepared for the stability assessment experiment of Fig. 3B, i.e. 13_A.S_2, was used for this assessment. This second comparative batch is encoded as 13_A.S_2 (B.T). The XRD spectrum of a sample of this second batch is compared with the one obtained from a sample from the first batch experiment, encoded as 13_A.S_1 (B.T.). The XRD spectra shown on Fig. 10 illustrate that the two samples, i.e. 13_A.S_1 (B.T.) and 13_A.S_2 (B.T.), contain the same compounds or species in substantially the same proportions. Thus, reproducibility of the process (100) is confirmed.

Date recue/Date Received 2018-01-09 [0154]Example 5 : Assessment of the stability of the second batch of Ni-UGSO
catalyst (13 A.S 2) with respect to mixed reforming of methane [0155]Referring to Fig. 11, an assessment of the stability of the second batch of Ni-UGSO catalyst (13_A.S_2) prepared for the reproducibility assessment of Figs.
3B and 10 has been conducted with respect to mixed reforming of methane. The experimental conditions were the following: mole ratio of CO2/CH4 = 0.97, mole ratio of H20/CH4 = 0.14 (7% H20), 3 plateaux of reaction temperatures spanning on 74 hours. Fig. 11 shows that the methane conversion remained stable at each temperature plateau, thus showing the stability of the Ni-UGSO catalyst. It is to be noted that the conversion of methane increased with temperature since the dry reforming reaction is endothermic, thus promoted with an increase of temperature.
[0156]Referring to Fig. 12, XRD spectra of Ni-UGSO catalysts having been used in the stability experimentation of Fig. 11 show that after 4 hours or 74 hours of reaction time, the catalysts have essentially the same composition. In addition, there seems to be no carbon deposition on these samples.
[0157]Two other samples of Ni-UGSO catalyst have been prepared in accordance with the process (100) described above. Here are some particularities of these samples. Both samples contain 13%-wt. Ni. The sample identified as 13_S.S (5) (B.T.) (S.S. referring to mithout addition of solvent ) has been subjected to the milling step (140) for 5 minutes and no acetone was added during its preparation. The sample identified as 13_S.S. (2.5) (B.T.) has been subjected to the milling step (140) for 2.5 minutes and again, no acetone was added during its preparation.
[0158]Fig. 13 compares the XRD spectra of the following samples: 13_S.S (5) (B.T.), 13_ S.S. (2.5) (B.T.) and 13_A.S_2 (B.T.), described above in example 4.
Fig. 13 shows that all three samples of Ni-UGSO catalyst have the same composition and crystalline structure before being subjected to the reforming reaction. Thus, it is shown that the addition of acetone during the process (100) for Date recue/Date Received 2018-01-09 forming the Ni-UGSO catalyst does not affect the final composition of a sample of catalyst obtained with this process (100).
[0159]Example 6: Assessment of catalytic performances of Ni-UGSO catalysts having been prepared with different parameters [0160]Referring to Figs. 14 to 16, different mixed reforming reactions have been conducted for 4 hours and have used the samples 13_S.S (5), 13_ S.S. (2.5) and 13_A.S_2 as catalyst. The experimental conditions were the following: mole ratio CO2/CH4= 0.97 and mole ratio H20/CH4 = 0.14 (7% H20). It appears from Figs. 14 to 16 that, without regard to how each of the catalyst was prepared, their catalytic performances were similar.
[0161]Fig. 17 compares XRD spectra of the samples 13_S.S (5) (A.T.), 13_S.S.
(2.5) (A.T.) and 13_A.S_2 (A.T.), i.e. the same samples as described above, but the XRD analyses were conducted after the 4 hours of reaction. It appears from Fig. 17 that the three samples have the same composition after having been used as catalyst for 4 hours and still do not show any signs of carbon deposition thereon.
[0162] Example 7: Assessment of the stability of the Ni-UGSO catalyst on steam reforming of methane [0163]A third Ni-UGSO catalyst batch (3rd batch) was prepared for this experiment.
The third batch of catalyst has been prepared using the same process (100) as described above, wherein the parameters were: 13%-w/w of Ni; 3 ml of water for lOg of catalyst; and 3 minutes of milling. The stability assessment experiment has been carried out for 7 days and 0.5 g of Ni-UGSO catalyst at 900 C and with a stoichiometric mole ratio H20/CH4 = 1.06.
[0164]Referring to Fig. 18 and 19, the results show that the methane conversion remained stable around 98% and a mole ratio H2/C0 close to 3.

Date recue/Date Received 2018-01-09 [01651A summary of the parameters used for the preparation of the catalysts described in the examples, as well as a summary of the parameters of the dry reforming reactions are provided below in Table 2 and Table 3 respectively.

Date recue/Date Received 2018-01-09 Q
su if 6' ¨I
,c) Example 1 Example 2 Example 3 Example 5 Example 6 Example 7 c Cr CD hat Preparation of a lot batch of a Ni-UGSO
Stability Stability Stability Assessm ant of Stability 6 Regeneration of Ni-UGSO Without Without Without tD 0 A) Parameters catalyst assessment as sessm ant of catalyst assessm ant solvent Wlthout solvent catalytic solvent solvent assessm ant of ry "A
re; of 1st batch 2nd batch of 2nd batch performances 3rd batch = = =-.1 dr NI-UGSO

Identification of the NI-UGSO NI-UGSO NI-UGSO
NI-UGSO Ni-UGSO NI-UGSO NI-UGSO NI-UGSO NI-UGSO NI-UGSO
(3rd CD .....
CD NIFe204 NI-UGSO
UGSO (13 &S.) l45 resulting catalyst (13_AS_1) (13_AS_2) AT(46)Cal. AT(7d) Cal. (13_AS_2) (13_S.S.) (5) (13_S.S.) (25) (13_AS_2) (13_S.S.) (5) 125) batch) 73 0 CD
0_ Ni-UGSO Ni-UGSO
AA
N.) Main reactant Fe2O3 UGSO UGSO UGSO UGSO
AT(4h) (13_A.S 1) UGSO UGSO UGSO UGSO UGSO UGSO UGSO

..=.
AT(7h7) , 9' =
- -Catalyst precursor Ni(NO3)2,6H,0 Ni(N0a)e6F120 -Ni(N00),61.120 NRN08),6H20 NKNO0,61.120 Ni(N002.61.120 Ni(NOtheH20 Ni(N08),6H20 Ni(NO)e6H20 Ni(NO0e6H,0 NRNOB)e6F120 ..... Quantity of catalyst i.i 6 precursor (%w/w( rt.
, , , , ' . _ CO S
Milling time to 15 10 to 15 - 10 to 15 5 - -5 5 25 5 5 2,5 3 CD
(minutes) Water Water liberated Water Water 0 Sdvent- Type and ID
Acetone -3 Acetone - 3 - Acetone- 3 Acetone -3 -- Acetone -3 liberated from from the Acetone -3 liberated from liberated from Water - 3 Quantity (ml / 10 g) sir , the precursor precursor , the precursor the precursor Drying time Stab 5 to 10 5to 10 5 to 10 5to 10 5 to 10 5 to 10 5 to 10 Stab 0 5 to 10 5 to 10 '<
- --V$
(hours) Drying temperature 105 105 th (C) Calcination time 12 12 . - - 12 12 12 12 12 12 12 12 (hours) Calcination 900 900 temperature (C) ' ' ' ' ' 2nd calcination time - - - -i (hours) - - - - -. 2nd calcination CO
-- - - - - - - - - - - temperature ( C) 900 l v en n ,....k 47, c, ur.

oe 4, .&..

Q
su Example 1 Example 2 Example 3 Example 5 Example 6 Example 7 .. ¨I
,c) c Ni-UGSO Ni-UGSO Ni-UGSO Ni-UGSO
CT
co Ni-UGSO (1st UGSO (13 A 1) (13A
Ni-UGSO BT Ni-UGSO Ni-UGSO NI-UGS0 Ni-UGSO Ni-UGSO NI-UGS0 Ni-UG80 Ni-UGSO (3rd Batch) 6 Catalyst NiFe20, _.S _.S_2) (1st Batch) AT AT(4h) AT(74) (13_AS_2) (13_8.S.) (5) (13_83)(2.5) (13_AS_2) (13_83)(5) (13_5.8)(2.5) batch) CD c=
la (1st Batch) (2nd Batch) Cal.
Cal.
=-.1 re.
. .
X Quantlty of 0.3 0.3 0.3 0.3 0.3 0.3 - - -0.3 - - 0.3 0.3 0.3 0.5 -0 0 I-, 0 catalyst (g) 0 ..., -4 l0 .i<1 Stoichiometric 4.1 0 a, 1 1 1 1.6 1.2 1 - - - 007 - - 007 0.97 097 -a ratio (C0i2/CHii) CD
F') o Stoichicmetric CD
..4.
-"c Co ratio _ . _ _ - - - - - 014 -- 0.14 014 0.14 1.06 V) 6 (H2o/cH4) o -p.
6 Temperature 800 - 896 - - 810 810 810 900 ,-IL
CO ( C) 0"
CD
Duration 4 4 4 168 168 4 and 168 - -- 4 to 74 - - 4 4 4 168 SD.
(hours) -ii .<
-ii CD
.41 g CO

CD
A) C) CO
=
¨%.
I
V
en n ,-, 47, ,...44 oe 4, .&..

[0166]It is to be understood that the above-described catalysts are contemplated to be used in various hydrocarbon reforming reactions, dry, steam or mixed. In an embodiment, the mole ratio of CO2/CH4 in the hydrocarbon reforming reaction is comprised between 0 and 2. In some implementations, the mole ratio H20/CH4 is comprised between 0 and 2.
[0167]Several alternative embodiments and examples have been described and illustrated herein. The embodiments of the invention described above are intended to be exemplary only. A person of ordinary skill in the art would appreciate the features of the individual embodiments, and the possible combinations and variations of the components. A person of ordinary skill in the art would further appreciate that any of the embodiments could be provided in any combination with the other embodiments disclosed herein. It is understood that the invention may be embodied in other specific forms without departing from the central characteristics thereof. The present examples and embodiments, therefore, are to be considered in all respects as illustrative and not restrictive, and the invention is not to be limited to the details given herein. Accordingly, while the specific embodiments have been illustrated and described, numerous modifications come to mind. The scope of the invention is therefore intended to be limited solely by the scope of the appended claims.

Date recue/Date Received 2018-01-09

Claims (58)

1- A process for producing a catalyst from a mining residue, comprising:
obtaining the mining residue comprising hematite, alumina and magnesia;
mixing the mining residue with a catalyst precursor comprising a catalytically active metal, in order to form a mixture;
milling the mixture for a period of time to form a milling product; and calcining the milling product to form the catalyst including an active metal-based spinel compound and an active metal-based solid solution.

2. A process for producing a catalyst from a mining residue, comprising:
obtaining the mining residue comprising hematite, alumina and magnesia, wherein a combination of the hematite, alumina and magnesia represents more than 50 wt% of the mining residue;
mixing the mining residue with a catalyst precursor comprising a catalytically active metal, in order to form a mixture;
milling the mixture for a period of time to form a milling product; and calcining the milling product to form the catalyst including an active metal-based spinel compound and an active metal-based solid solution.

3. The process according to claim 2, wherein the combination of the hematite, alumina and magnesia represents about 75 wt% or more of the mining residue.

4. The process of claim 2 or 3, wherein the combination of the hematite, alumina and magnesia represents about 80 wt% or more of the mining residue.

5. The process of any one of claims 1 to 4, wherein the mining residue comprises about 0.18 wt% or less of SiO2.

6. The process according to any one of claims 1 to 5, wherein the mining residue comprises a metallurgical tailing.

7. The process according to any one of claims 1 to 6, wherein the mining residue comprises at least one of an iron-based spinel compound, an aluminium-based spinel compound, and a magnesium-based spinel compound.

8. The process according to claim 7, wherein the at least one of the iron-based spinel compound, the aluminium-based spinel compound, and the magnesium-based spinel compound is at least one of MgAl204, MgFe204 and FeAl204.

9. The process according to claim 7 or 8, wherein at least one of the at least one of the iron-based spinel compound, the aluminium-based spinel compound, and the magnesium-based spinel compound is a spinel solid solution.

10. The process according to claim 9, wherein the spinel solid solution comprises Mg(Fe,Al)204.

11. The process according to claim 10, wherein the catalytically active metal is selected from the group consisting of : nickel, cobalt, molybdenum, copper and chrom ium.

12. The process according to any one of claims 1 to 11, wherein the active metal-based solid solution comprises a Mx0y-Mg0 solid solution, where M is selected from the group consisting of: nickel, cobalt, molybdenum, copper and chromium.

13. The process according to any one of claims 1 to 12, wherein the active metal-based solid solution comprises a NiO-Mg0 solid solution.

14. The process according to any one of claims 1 to 13, wherein the mining residue is in the form of a micrometric powder.

15. The process according to any one of claims 1 to 13, wherein the obtaining of the mining residue comprises comminuting the mining residue into a micrometric powder.

16. The process according to claim 14 or 15, wherein the micrometric powder includes particles characterized by a size comprised between about 1 pm and about 100 pm.

17. The process according to any one of claims 14 to 16, wherein the obtaining of the mining residue comprises adding a binding agent to the micrometric powder, mixing the binding agent and the micrometric powder, and pelletizing the mixture to produce millimetric sized pellets.

18. The process according to any one of claims 1 to 17, wherein the mixing of the mining residue comprises adding the catalyst precursor in an amount corresponding to a stoichiometry of reactions forming the active metal-based spine! compound.

19. The process according to any one of claims 1 to 17, wherein the mixing of the mining residue comprises adding the catalyst precursor in an amount in excess or deficient with respect to a stoichiometry of reactions forming the active metal-based spinel compound.

20. The process according to any one of claims 1 to 17, wherein the catalyst precursor is added in a stoichiometric mole ratio of 0.5 to 1.5 with reactions forming the active metal-based spinel compound.

21. The process according to any one of claims 1 to 20, wherein the mixing of the mining residue comprises adding at least one of water and acetone with the catalyst precursor.

22. The process according to any one of claims 1 to 21, wherein the catalyst precursor comprises at least one of nickel, cobalt, molybdenum, copper and chrom ium.

23. The process according to any one of claims 1 to 22, wherein the catalyst precursor comprises at least one of a nitrate, a sulfite, and a chloride.

24. The process according to any one of claims 1 to 23, wherein the catalyst precursor is a hydrated precursor.

25. The process according to any one of claims 1 to 24, wherein the catalyst precursor is an inorganic or organic nickel salt.

26. The process according to any one of claims 1 to 24, wherein the catalyst precursor comprises nickel nitrate hexahydrate (Ni(NO3)2.6H20).

27. The process according to claim 26, wherein the nickel nitrate hexahydrate is added in an amount corresponding to a stoichiometry of reactions forming NiFe204 and NiAl204.

28. The process according to claim 26, wherein the nickel nitrate hexahydrate is added in an amount in excess with respect to a stoichiometry of reactions forming NiFe204 and NiAl204.

29. The process according to any one of claims 1 to 24, wherein the catalyst precursor comprises nickel chloride (NiCl2).

30. The process according to claim 29, wherein the catalyst precursor comprises hexahydrated nickel chloride (NiCl2.6H20).

31. The process according to any one of claims 1 to 30, further comprising drying the milling product to obtain a dry milling product and wherein the calcining of the milling product comprises calcining the dried milling product.

32. The process according to claim 31, wherein the drying of the milling product is carried out at a drying temperature comprised between about 75 C and about 130 C.

33. The process according to any one of claims 1 to 32, wherein the milling of the mixture is carried out for a milling time period comprised between about 2 and about 10 m inutes.

34. The process according to any one of claims 1 to 33, wherein the calcining of the milling product is carried out for a calcining time period comprised between about 1 and about 12 hours.

35. The process according to any one of claims 1 to 34, wherein the calcining of the milling product is carried out at a calcining temperature comprised between about 850 C and about 1100 C.

36. The process according to claim 35, wherein the calcining temperature is comprised between about 900 C and about 950 C.

37. The process according to any one of claims 1 to 36, wherein the mining residue comprises a waste product obtained from a beneficiation plant of an ilmenite ore (FeTiO3) metallurgical complex.

38. The process according to any one of claims 1 to 37, further comprising regenerating the catalyst by subjecting the catalyst to a further calcining.

39. The catalyst obtained by the process as claimed in any one of claims 2 to 38.

40. Use of a catalyst obtained from the process according to any one of claims 2 to 38 for at least one of production of syngas, production of methane, hydrocarbons reforming, hydrogen production, preparation of feed gas for fuel cell units, oil refining, hydrotreatment, hydrocracking and isomerization.

41. A process for at least one of production of methane, hydrocarbons reforming, hydrogen production, preparation of feed gas for fuel cell units, oil refining, hydrotreatment, hydrocracking and isomerization using a catalyst obtained from the process in accordance with any one of claims 2 to 38.

42. A catalyst for use in at least one of production of syngas, production of methane, hydrocarbons reforming, hydrogen production, preparation of feed gas for fuel cell units, oil refining, hydrotreatment, hydrocracking and isomerization, comprising an active metal-based spinel compound and an active metal-based solid solution originating from a solid-state reaction between a catalyst precursor, comprising a catalytically active metal, and a mining residue comprising hematite, alumina, and magnesia, wherein a combination of the hematite, alumina and magnesia represents more than 50 wt% of the mining residue.

43. The catalyst according to claim 42, wherein the combination of the hematite, alumina and magnesia represents about 75 wt% or more of the mining residue.

44. The catalyst of claim 42 or 43, wherein the combination of the hematite, alumina and magnesia represents about 80 wt% or more of the mining residue.

45. The catalyst of any one of claims 42 to 45, wherein the mining residue comprises about 0.18 wt% or less of SiO2.

46. The catalyst according to any one of claims 42 to 45, wherein the active metal-based solid solution comprises a NiO-Mg0 solid solution.

47. The catalyst according to any one of claims 42 to 46, wherein the mining residue comprises a metallurgical tailing.

48. The catalyst according to claim 47, wherein the mining residue comprises a waste product obtained from a beneficiation plant of an ilmenite ore (FeTiO3) metallurgical complex.

49. The catalyst according to any one of claims 42 to 48, wherein the mining residue comprises at least one of an iron-based spinel compound, an aluminium-based spinel compound, and a magnesium-based spinel compound.

50. The catalyst according to claim 49, wherein the at least one of the iron-based spinel compound, the aluminium-based spinel compound, and the magnesium-based spinel compound is at least one of MgAl204, MgFe204 and FeAl204.

51. The catalyst according to claim 49 or 50, wherein at least one of the at least one of the iron-based spinel compound, the aluminium-based spinel compound, and the magnesium-based spinel compound is a spinel solid solution.

52. The catalyst according to claim 51, wherein the spinel solid solution comprises Mg(Fe,Al)204 and at least one of the nickel based spine!.

53. The catalyst according to any one of claims 42 to 52, wherein the mining residue is in the form of a micrometric powder including particles characterized by a size comprised between about 1 pm and about 100 pm.

54. The catalyst according to any one of claims 42 to 53, wherein the catalyst precursor is present in an amount corresponding to a stoichiometry of reactions forming the active metal-based spinel compound in the catalyst.

55. The catalyst according to any one of claims 42 to 53, wherein the catalyst precursor is present in a stoichiometric mole ratio of 0.5 to 1.5 with reactions forming the active metal-based spinel compound in the catalyst.

56. The catalyst according to any one of claims 42 to 55, wherein the catalytically active metal comprises at least one of nickel, cobalt, molybdenum, copper and chrom ium.

57. The catalyst according to any one of claims 42 to 56, wherein the catalytically active metal comprises nickel.

58. The catalyst according to any one of claims 42 to 57, wherein the catalytically active metal comprises at least one of a nitrate, a sulfite, and a chloride.