WEAR RESISTANT MINING FE ALLOY MATRIX AND SPINEL CERAMIC COMPOUND COMPOSITE

Abstract

A metal matrix composite to high tolerate wear as a property has been produced by infiltration casting of a Fe Alloy and a spinel ceramic by using a material design for i) metal transport phenomena conditions, ii) predefined wetting and capillarity and iii) processing child insert/mother casting methodology to produce a final casting in shape and form to meet the needs of a mining end user.

Claims

1. A casting method of producing a wear resistant mining casting material, said method comprising: a sand-casting model in a two-step approach by: (1) selecting an Fe alloy metal and a spinel ceramic having a compatible Coefficient of Thermal Expansion (CTE), a compatible wetting contact angle (WCA), or a combination thereof, wherein the Fe alloy metal has a compatible CTE of from about 10 ppm ? C..sup.?1 to about 21 ppm ? C..sup.?1 and the spinel ceramic has a compatible CTE of from about 6 ppm ? C..sup.?1 to about 11 ppm ? C..sup.?1; (2) manufacturing by an infiltration process a child metal insert casting comprising the compatible Fe alloy metal and the spinel ceramic; and (3) placing the resultant child insert casting into a mother holding casting for specific design and locations using mechanical fixing chaplets before final Fe alloy metal pouring and solidification of a product.

2. The method of claim 1, wherein the child metal insert consists of a metal matrix of similar characteristics of chemistry, metallurgy and physical appearance as the mother holding casting, such as most steels (0.0-2.2% C) and irons (>2.2% C).

3. The method of claim 1, wherein the spinel ceramic materials and the Fe alloy metal produce a wetting contact angle (?)<90? and cast metal flow ranges from about 15 in/s to about 60 in/s.

4. The method of claim 1, wherein the spinel ceramic and the Fe alloy metal produce an interface between 1-10 nm to 50-500 ?m.

5. The method of claim 1, where the spinel ceramic has (i) a coefficient thermal expansion (CTE-SCP) of from about 60% to about 70% of the CTE of the Fe alloy matrix (CTE-FEAM) or (ii) a CTE-SCP of from about 5% to about 10% of the CTE-FEAM.

6. The method of claim 1, wherein the ceramic material includes a spinel ceramic having a thermal conductivity of from about 20 W/kK to about 55 W/mK, a flexural strength >2500 Kg/cm.sup.2, and an enthalpy of formation of from about 25 kJ/mol to about 200 kJ/mol.

7. The method of claim 6, wherein the child metal insert comprises: (i) about 5% by volume to about 60% by volume of the spinel ceramic, (ii) from about 30% by volume to about 40% by volume of the spinel ceramic, or (ii) about 50% by volume of the spinel ceramic.

8. The method of claim 6, wherein the spinel ceramic has a size of: (i) from about 25 nm to about 150 nm, (ii) from about 50 ?m to about 500 ?m, (iii) from about 1 mm to about 10 mm, (iv) or a combination thereof.

9. The method of claim 6, wherein the spinel ceramic is produced by a fusion process, a sintering process, or naturally as obtained from a mine.

10. The method of claim 6, wherein the spinel ceramic is an aluminum spinel, an iron spinel, a chromium spinel, a cobalt spinel, a vanadium spinel, a mineral having a spinel structure, or a combination thereof.

11. The method of claim 1, wherein the mother holding casting comprises a single casting fill rate of about 1 dm.sup.3/s to about 2 dm.sup.3/s.

12. The method of claim 1, wherein the mother holding casting comprises a full system fill rate of about 3 dm.sup.3/s to about 6 dm.sup.3/s.

13. The method of claim 1, wherein a thermal gradient in the xy-plane for the child insert in the mother holding casting is not more than about 25? C./m.

14. The wear resistant mining casting material obtained by the method of claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] FIG. 1. Schematic of components used in process. 1) Ceramic particles, 2) Inserts representation (Child Casting), 3) Casting product representation (Mother Casting) and 4) Fe Molten Metal.

[0027] FIG. 2. Inserts (Child Casting). Where 1 represent the loosen ceramic particles, 2 represent the interface of ceramic-metal packaging and 3 Fe metal solidified.

[0028] FIG. 3. Casting product representation (Mother Casting). Where 1 represent the Fe metal solidified/heat treated, 2 represent the Inserts (Child Casting), 3 represent the interface insert-mother casting (Chaplets locations) and 4 work surfaces (composite improvement).

DETAILED DESCRIPTION

[0029] The child metal insert consists of a metal matrix of similar characteristics of chemistry, metallurgy and physical appearance as the mother holding casting. This includes most steels (0.0-2.2% C) and irons (>2.2% C). In one aspect, the metal matrix is a Fe alloy metal with C (0.5-2.5%), Mn (0.5-1%), Cr (2-18%), Ni (0.1-2%) and Mo (0.1-1%). In another aspect, the metal matrix is a Fe alloy metal with compositional amounts (and percent eutectic carbide (% EC) as tabulated below.

TABLE-US-00001 Alloy C Si Cr Mn Mo S P % EC 302 2.4-2.7 0.3-0.8 14.0-17.0 1.35-1.75 0.8-1.2 ?0.06 ?0.1 26.7 ? 3.2 306 2.4-2.7 0.3-0.8 14.0-17.0 0.5-0.8 2.4-2.8 ?0.06 ?0.1 22.0 ? 3.8 SP1 1.5-2.65 0.3-0.8 16.0-19.0 0.6-0.9 1.0-1.4 ?0.06 ?0.1 22.0 ? 2.4 482 3.3-3.5 0.3-0.7 22.0-26.0 1.0-1.4 0.8-1.4 ?0.06 ?0.1 36.1 ? 2.2 540 2.7-3.0 0.3-0.7 25.0-29.0 1.0-1.4 0.15-0.45 ?0.06 ?0.1 31.2 ? 1.7

[0030] The ceramic materials contemplated herein comprise spinel based Spinel (Mg, Fe, Zr, Zn, Ca, Co, Ni, Zn, Ba, Ti, Li).sub.x-n(Al,Cr).sub.x-mO.sub.x-y. All ranges of Spinel compositions including Metal A+Metal B+Oxygen are included in the present disclosure.

[0031] The Spinels are any of a class of minerals of general formulation AB.sub.2X.sub.4 which crystallize in the cubic (isometric) crystal system, with the X anions (typically chalcogens, like oxygen and sulfur) arranged in a cubic close-packed (ccp) lattice and the cations A and B occupying some or all of the octahedral and tetrahedral sites in the lattice. [8,9] Although the charges of A and B in the prototypical spinel structure are +2 and +3, respectively (viz., A.sup.2+B.sup.3+.sub.2X.sup.2?.sub.4), other combinations incorporating divalent, trivalent, or tetravalent cations, including magnesium, zinc, iron, manganese, aluminum, chromium, titanium, and silicon, are also contemplated. The anion is normally oxygen; when other chalcogenides constitute the anion sublattice the structure is referred to as a thiospinel.

[0032] A and B can also be the same metal with different valences, as is the case with magnetite, Fe.sub.3O.sub.4 (as FeFe.sup.2+Fe.sup.3+.sub.2O.sup.2?.sub.4), which is the most abundant member of the spinel group. [10] Spinels are grouped in series by the B cation. Members of the spinel group include [11]: (i) an aluminum spinel (e.g., Spinel (MgAl.sub.2O.sub.4) Gahnite (ZnAl.sub.2O.sub.4), Hercynite (FeAl.sub.2O.sub.4), Galaxite (MnAl.sub.2O.sub.4), Pleonaste ((Mg,Fe)Al.sub.2O.sub.4); (ii) an iron spinel (e.g., Cuprospinel (CuFe.sub.2O.sub.4), Franklinite ((Fe,Mn,Zn)(Fe,Mn).sub.2O.sub.4), Jacobsite (MnFe.sub.2O.sub.4), Magnesioferrite (MgFe.sub.2O.sub.4), Magnetite (FeFe.sub.2O.sub.4, where one Fe is +2 and two Fe's are +3, respectively), Trevorite (NiFe.sub.2O.sub.4), Ulv?spinel (TiFe.sub.2O.sub.4), and zinc ferrite: ((Zn, Fe)Fe.sub.2O.sub.4)); (iii) a chromium spinel (e.g., Chromite (FeCr.sub.2O.sub.4), Magnesiochromite (MgCr.sub.2O.sub.4), Zincochromite (ZnCr.sub.2O.sub.4)), (iv) a cobalt spinel (e.g., Manganesecobaltite (Mn.sub.1.5Co.sub.1.5O.sub.4[12]; (v) a vanadium spinel (e.g., Coulsonite (FeV.sub.2O.sub.4), Magnesiocoulsonite (MgV.sub.2O.sub.4), and (vi) other mineral having a spinel structure (e.g., Ringwoodite: (Mg,Fe).sub.2SiO.sub.4), Taaffeite (BeMgAl.sub.4O.sub.8), and Musgravite (Be(Mg,Fe,Zn).sub.2Al.sub.6O.sub.12)).

[0033] Wetting conditions of a Fe alloy metal with Spinel ceramics show case its adhesion behavior by addressing contact angles and surface tensions as function of alloy melting point (s), surface roughness values, particles sizes, crystallographic planes, grades of purity, alloy composition and thermodynamic interfaces conditions. The designed contact angles, ?, between the pair Fe alloy metal and Spinel ceramics are in wetting of ?<90? following the equilibrium of a sessile drop model.

[0034] The manufactured liner may undergo a subsequent heat treatment depending on customer requirements. Therefore, some compatibility from the viewpoint of temperature behavior. The Fe alloy metal covered uses a CTE of about 10?10.sup.?6 (? C.).sup.?1 to about 21?10.sup.?6 (? C.).sup.?1 and the spinel ceramics of about 6?10.sup.?6 (? C.).sup.?1 to about 11?10.sup.?6 (? C.).sup.?1. Alternatively expressed, the Fe alloy metal has a CTE that ranges from about 10 ppm ? C..sup.?1 to about 21 ppm ? C..sup.?1 and the spinel ceramic has a CTE that ranges from about 6 ppm ? C..sup.?1 to about 11 ppm ? C..sup.?1; where ppm stands for parts per million and corresponds to 10?10.sup.?6.

[0035] In one aspect, the Fe alloy metal has a CTE (in ppm ? C..sup.?1) of: 10.1, 10.2, 10.3, 10.4, 10.5, 10.6, 10.7, 10.8, 10.9, 11.0, 11.1, 11.2, 11.3, 11.4, 11.5, 11.6, 11.7, 11.8, 11.9, 12.0, 12.1, 12.2, 12.3, 12.4, 12.5, 12.6, 12.7, 12.8, 12.9, 13.0, 13.1, 13.2, 13.3, 13.4, 13.5, 13.6, 13.7, 13.8, 13.9, 14.0, 14.1, 14.2, 14.3, 14.4, 14.5, 14.6, 14.7, 14.8, 14.9, 15.0, 15.1, 15.2, 15.3, 15.4, 15.5, 15.6, 15.7, 15.8, 15.9, 16.0, 16.1, 16.2, 16.3, 16.4, 16.5, 16.6, 16.7, 16.8, 16.9, 17.0, 17.1, 17.2, 17.3, 17.4, 17.5, 17.6, 17.7, 17.8, 17.9, 18.0, 18.1, 18.2, 18.3, 18.4, 18.5, 18.6, 18.7, 18.8, 18.9, 19.0, 19.1, 19.2, 19.3, 19.4, 19.5, 19.6, 19.7, 19.8, 19.9, 20.0, 20.1, 20.2, 20.3, 20.4, 20.5, 20.6, 20.7, 20.8, 20.9, and 21.0.

[0036] In another aspect, the spinel ceramic has a CTE (in ppm ? C..sup.?1) of: 6.0, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, 7.0, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9, 8.0, 8.1, 8.2, 8.3, 8.4, 8.5, 8.6, 8.7, 8.8, 8.9, 9.0, 9.1, 9.2, 9.3, 9.4, 9.5, 9.6, 9.7, 9.8, 9.9, 10.0, 10.1, 10.2, 10.3, 10.4, 10.5, 10.6, 10.7, 10.8, 10.9, and 11.0 The ceramic material in size range between nano, micro and mm scale are considered in this study are based on Spinel (Mg,Fe, Zr, Zn, Ca, Co, Ni, Zn, Ba, Ti, Li).sub.x-n(Al,Cr).sub.x-mO.sub.x-y. In one aspect, the spinel ceramic particles have a size of: (i) from about 25 nm to about 150 nm, (ii) from about 50 ?m to about 500 ?m, (iii) from about 1 mm to about 10 mm, (iv) or a combination thereof.

[0037] Spinel may be fused (obtained from a fusion process), sintered (obtained from a sintering process), or natural crystals directly from the mine source. The ceramic particles shapes also cover spherical, non-spherical (fibers like) and irregular shape and or combination of the same. The ceramic materials can be of purity from >80% and the remaining other oxide and non-oxide compounds not exceeding the remaining from its solid solution compound. It also includes others surface conditioners for the ceramic surfaces such as special coatings (a graphene, a metal nitrate, a metal carbide), brazing, etchers, powder metal (Al, Ti, Cr, Mn, Mg, Ni, Cu, Au, Pd, Ag, Zr, Co, Fe Sn) and or layers of materials in addition to the ceramic matrix such as pretreatment of particles to add a secondary phase.

[0038] The content of spinel ceramic materials in the insert is between 5 and 60% by volume, preferably between 30 to 40% and advantageously of the order of 50%.

[0039] The Spinel ceramic particles are aggregated in granular form to the child insert of predefined dimensions and shapes. This depends of the design and the use of the mother castings predefined by an end user or by design analysis.

[0040] The invention is based on the finding the wetting conditions of Fe alloys and Spinel ceramics where contact angles are <90? and interface formations are within 1-10 nm to 50-500 ?m. The Spinel ceramics are studied for compositional ranges, roughness values, crystallographic orientations in pair with Fe alloy composition and its metal flow to evaluate its wetting, adhesion and joining behavior. In one aspect, the coefficient thermal expansion (CTE) of the ceramic material has a value of about 60 to about 70% of that of Fe alloy matrix. In another aspect, the CTE of the ceramic material has a value of about 5% to about 10% of the CTE of the Fe alloy matrix. It is contemplated that a uniform distribution of CTEs may result in reducing ceramic or casting cracking.

[0041] In an aspect of the process disclosed herein, one may select a metal flow rate, inside the casting mold, in combination with wetting contact angles. It is believed that selection of a compatible metal flow rate and wetting contact angles produces a homogeneous casting that minimizes weakening effects of ceramic particles during metal casting and solidification in the final microstructure. In one aspect, the metal case flow rate ranges from about 15 in/s to about 60 in/s where most cases seeing a pair of metal-ceramic wetting angles to <90 degrees.

[0042] In another aspect of the method described herein the infiltration process comprises a single casting fill rate of about 1 dm.sup.3/s to about 2 dm.sup.3/s, including all values in between, such as, for example 1.1 dm.sup.3/s, 1.2 dm.sup.3/s, 1.3 dm.sup.3/s, 1.4 dm.sup.3/s, 1.5 dm.sup.3/s, 1.6 dm.sup.3/s, 1.7 dm.sup.3/s, 1.8 dm.sup.3/s, and 1.9 dm.sup.3/s.

[0043] In another aspect of the method described herein the infiltration process comprises a full system fill rate of about 3 dm.sup.3/s to about 6 dm.sup.3/s, including all values in between, such as, for example 3.1 dm.sup.3/s, 3.2 dm.sup.3/s, 3.3 dm.sup.3/s, 3.4 dm.sup.3/s, 3.5 dm.sup.3/s, 3.6 dm.sup.3/s, 3.7 dm.sup.3/s, 3.8 dm.sup.3/s, 3.9 dm.sup.3/s, 4.1 dm.sup.3/s, 4.2 dm.sup.3/s, 4.3 dm.sup.3/s, 4.4 dm.sup.3/s, 4.5 dm.sup.3/s, 4.6 dm.sup.3/s, 4.7 dm.sup.3/s, 4.8 dm.sup.3/s, 4.9 dm.sup.3/s, 5.1 dm.sup.3/s, 5.2 dm.sup.3/s, 5.3 dm.sup.3/s, 5.4 dm.sup.3/s, 5.5 dm.sup.3/s, 5.6 dm.sup.3/s, 5.7 dm.sup.3/s, 5.8 dm.sup.3/s, and 5.9 dm.sup.3/s.

[0044] In one aspect, the spinel ceramic particles have a thermal conductivity from about 20 W/mK to about 55 W/mK, a flexural strength >2500 kg/cm.sup.2, and an enthalpy of formation of from about 25 kJ/mol to about 200 kJ/mol.

Example

[0045] A white iron/spinel ceramic composite blue bar was manufactured as a part of this investigation. An exemplary white iron may be a 306 alloy, as described herein. An exemplary spinel ceramic corresponds to MgAl.sub.2O.sub.4 having a ccp lattice.

[0046] Blue bar castings were obtained bottom fed with in-gates located on the drag sand mold containing a uniform distribution of loose spinel particles (MgAl.sub.2O.sub.4) at a given flow rate, see, e.g., infra. In one example the spinel particles having a size of from about 1 to about 3 mm were present at about 7.5 vol %. In other instances, blue bar castings were fed along the parting lines.

[0047] Molten metal near the in-gate wetted spinel particles in 10 mm thick layers. Large amounts of shrinkage macroporosity were identified at the in-gate near regions where wetting occurred. Macroporosity was interconnected and extended along the longitudinal axis of the blue bar at the in-gate.

[0048] X-ray EDS Hypermaps revealed no evidence of interfacial phases or metal penetration along wetted white iron/spinel particle interfaces. These interfaces were mechanical in nature where wetted particles were held in compression due to molten metal shrinkage during solidification.

[0049] Separately, thermal gradients developed in the pouring process were examined to improve probability of a sound casting being produced. Thermal gradients where determined using the Magmasoft simulation software and measured using thermal couples placed on the surface of the casting upon the completion of the filling phase. Castings had approximate dimensions of 0.31?1.26?0.08 meters in the x, y, and z directions respectively, which may alternatively be expressed in decimeters (dm) as 3.1 dm?12.6 dm?0.8 dm in the x, y, and z directions, respectively.

[0050] The average temperature of each casting surface can be seen in Tables 1 and 2. Three different gravity fed runner designs were simulated. Design 1 (D1) was fed through the short end of the castings, design 2 (D2) was fed through the risers, and design 3 (D3) being fed through a combination of the risers and the side of the casting. The difference between the opposite sides was calculated based off these averages and shown in Table 3. This temperature difference was then divided by the cross-sectional thickness in meters to determine the thermal gradient as recorded in Table 3.

TABLE-US-00002 TABLE 1 Ceramic Temperature ? C. Design X1 X2 Y1 Y2 Z1 Z2 D1 1359 ? 5 1359 ? 5 1360 ? 14 1351 ? 9 1357 ? 8 1354 ? 8 D2 1359 ? 5 1364 ? 5 1354 ? 8 1357 ? 5 1358 ? 9 1354 ? 8 D3 1357 ? 4 1365 ? 5 1354 ? 8 1354 ? 8 1356 ? 8 1354 ? 8

TABLE-US-00003 TABLE 2 Iron Temperature ? C. X1 X2 Y1 Y2 Z1 Z2 D1 1359 ? 21 1358 ? 18 1369 ? 12 1333 ? 8 1349 ? 18 1356 ? 12 D2 1327 ? 11 1347 ? 7 1339 ? 9 1333 ? 8 1336 ? 12 1350 ? 9 D3 1345 ? 8 1360 ? 5 1347 ? 7 1339 ? 8 1343 ? 9 1350 ? 10

TABLE-US-00004 TABLE 3 Ceramic (Alumina) Insert White Iron (306 alloy) Insert Runners X Y Z X Y Z D1 ?T (? C.) 0.1 9.7 1.6 1.2 33.1 7.2 D2 ?T (? C.) 4.5 0.4 2.8 18.8 6.2 13.6 D3 ?T (? C.) 7.7 2.6 1.5 15.7 7.8 6.6 D1 Thermal 0.2 7.7 20.1 3.7 26.3 89.7 Gradient (? C./m) D2 Thermal 14.5 0.3 35.5 60.6 4.9 169.5 Gradient (? C./m) D3 Thermal 24.8 2.0 19.1 50.8 6.2 82.3 Gradient (? C./m)

[0051] Magmasoft software was used to simulate the filling rate of a mold with four casting cavities and a 28660 lbs ladle, where the filling times range from about 30 s to about 38 s. Simulated fill rate was determined by dividing the total mass of the of the castings which was then divided by the total filling time. This was then converted to volume using the density of material at the pouring temperature. Current rigging includes four castings per mold however, this process could be performed a different number of castings per mold without deviating from the essence of this process. The full system fill rates range from about 3 dm.sup.3/s to about 6 dm.sup.3/s, while the single casting fill rates range from about 1 dm.sup.3/s to about 2 dm.sup.3/s.

[0052] The Table 3 data shows that the thermal gradient for the ceramic insert in the xy-plane to be not more than about 25? C./m, while the thermal gradient for the 306 alloy insert to be not more than about 60? C./m. In one aspect, it is contemplated that the thermal gradient (regardless of insert) is minimized in the xy-plane such that directional solidification occurs primarily in the z-direction (along the axis of the riser), which allows for final solidification in the riser(s), as opposed to the casting.

Practical Utility

[0053] The materials methodology of the manufacture process disclosed herein relates to casting liners for grinding and milling of larger size dimensions for applications of mills, crushers, shutters, containers, pumps, pipes, carriers and other special mining equipment. The manufacturing process using ceramic particles can develop composites of thin <25 mm and thicker liner sections of >25 mm by using the manufacturing methods disclosed herein.

Disclosed Aspects

[0054] Aspect 1 relates to a casting method of producing a wear resistant mining casting material, said method comprising: a sand-casting model in a two-step approach by: [0055] (1) selecting an Fe alloy metal and a spinel ceramic having a compatible Coefficient of Thermal Expansion (CTE), a compatible wetting contact angle (WCA), or a combination thereof; [0056] wherein the Fe alloy metal has a compatible CTE of from about 10 ppm ? C..sup.?1 to about 21 ppm ? C..sup.?1 and the spinel ceramic has a compatible CTE of from about 6 ppm ? C..sup.?1 to about 11 ppm ? C..sup.?1; [0057] (2) manufacturing by an infiltration process a child metal insert casting comprising the compatible Fe alloy metal and the spinel ceramic; and [0058] (3) placing the resultant child insert casting into a mother holding casting for specific design and locations using mechanical fixing chaplets before final Fe alloy metal pouring and solidification of a product.

[0059] Aspect 2 relates to Aspect 1, wherein the child metal insert consists of a metal matrix of similar characteristics of chemistry, metallurgy and physical appearance as the mother holding casting, such as most steels (0.0-2.2% C) and irons (>2.2% C).

[0060] Aspect 3 relates to any one of Aspects 1-2, wherein the spinel ceramic materials and the Fe alloy metal produce a wetting contact angle (?)<90? and cast metal flow ranges from about 15 in/s to about 60 in/s.

[0061] Aspect 4 relates to any one of Aspects 1-3, wherein the spinel ceramic and the Fe alloy metal produce an interface between 1-10 nm to 50-500 ?m.

[0062] Aspect 5 relates to any one of Aspects 1-4, where the spinel ceramic has (i) a coefficient thermal expansion (CTE-SCP) of from about 60% to about 70% of the CTE of the Fe alloy matrix (CTE-FEAM) or (ii) a CTE-SCP of from about 5% to about 10% of the CTE-FEAM.

[0063] Aspect 6 relates to any one of Aspects 1-5, wherein the ceramic material includes a spinel ceramic having a thermal conductivity of from about 20 W/kK to about 55 W/mK, a flexural strength >2500 Kg/cm.sup.2, and an enthalpy of formation of from about 25 kJ/mol to about 200 kJ/mol.

[0064] Aspect 7 relates to any one of Aspects 1-6, wherein the child metal insert comprises: (i) about 5% by volume to about 60% by volume of the spinel ceramic, (ii) from about 30% by volume to about 40% by volume of the spinel ceramic, or (ii) about 50% by volume of the spinel ceramic.

[0065] Aspect 8 relates any one of Aspects 1-7, wherein the spinel ceramic has a size of: (i) from about 25 nm to about 150 nm, (ii) from about 50 ?m to about 500 ?m, (iii) from about 1 mm to about 10 mm, (iv) or a combination thereof.

[0066] Aspect 9 relates to any one of Aspects 1-8, wherein the spinel ceramic is produced by a fusion process, a sintering process, or naturally as obtained from a mine.

[0067] Aspect 10 relates to any one of Aspects 1-9, wherein the spinel ceramic is an aluminum spinel, an iron spinel, a chromium spinel, a cobalt spinel, a vanadium spinel, a mineral having a spinel structure, or a combination thereof.

[0068] Aspect 11 relates to any one of Aspects 1-10, wherein the mother holding casting comprises a single casting fill rate of about 1 dm.sup.3/s to about 2 dm.sup.3/s.

[0069] Aspect 12 relates to any one of Aspects 1-11, wherein the mother holding casting comprises a full system fill rate of about 3 dm.sup.3/s to about 6 dm.sup.3/s.

[0070] Aspect 13 relates to any one of Aspects 1-12, wherein a thermal gradient in the xy-plane for the child insert in the mother holding casting is not more than about 25? C./m.

[0071] Aspect 14 relates to the wear resistant mining casting material obtained by any one of the methods of Aspects 1-13.

CITED INFORMATION

[0072] Information disclosed here is hereby incorporated by reference, including the subject matter of U.S. Provisional Patent Application No. 63/121,449, filed on Dec. 4, 2020. If an incorporated term conflicts with the meaning of a term disclosed herein, the meaning of the term disclosed herein controls. [0073] [1] Ansell, G., Oxide Dispersion Strengthening, G. Ansel, et al,. Editors, Gordon and Breach, New York (1968), p 61. [0074] [2] Roberts et al. J.I.S.I. (1968) (206): 375-384. [0075] [3] Grant NJ In: Frontiers in materials technologies. Elsevier, New York, 1985, p 125. [0076] [4] Baier et al., Adhesion: Mechanisms That Assist or Impede It, Science (1968) 162(3860): 1360-1368. [0077] [5] Jangehud et al. In: Proc. 21st Biennial Conf. on Carbon, Buffalo, NY, Jun. 13-18, 1993. [0078] [6] Chawla et al. In: High performance composites: commonalty of phenomena. TMS, Warrendale, P A, 1994, p 207. [0079] [7] Aguilar-Santillan, J. Wetting of alumina and spinel single crystals by molten aluminum, PhD diss., University of Alabama, (2004). Available from ProQuest Dissertations Publishing (UMI No. 3190074). [0080] [8] Robert J. Naumann: Introduction to the Physics and Chemistry of Materials CRC Press, 2008, ISBN 978-1-4200-6134-5. [0081] [9] H-J Meyer: Festk?rperchemie in: H-J Meyer (ed.), Riedel Moderne Anorganische Chemie, Walter de Gruyter, 2012, ISBN 978-3-11-024900-2. [0082] [10] Ernst, W. G. (1969). Earth Materials (Print ed.). Englewood Cliffs, NJ: Prentice-Hall. p. 58. [0083] [11] Spinel Group at mindat.org (viz., www.mindat.org/min-29156.html, accessed on Dec. 2, 2020). [0084] [12] American Elements, Manganese Cobalt Oxide, Spinel Powder.