BACKGROUND ART A balance weight also termed a counterbalance or counterweight is used to maintain an external force and balance operated on a self weight of an apparatus or the apparatus itself.

As a material for a mechanical component such as the balance weight, a homogeneous mineral and a heterogeneous rock which are geological units are manufactured according to a refining process of an integrated iron and steel mill by using a high temperature thermal energy (normally over 1300°C), which increases a manufacturing cost and complicates a series of manufacturing processes.

DISCLOSURE OF THE INVENTION An object of the present invention is to provide a compound iron and mineral material including a mineral rock and a fragment iron as essential elements which can be easily manufactured at a low cost by mixing a natural mineral rock and a fragment iron as essential elements, mixing the resultant material with a synthetic resin such as PP, PE, nylon, ABS and HIPS, various adhesives and additives, performing primary compression/injection molding according to chemical elements, physical properties and yield status of the mineral material, and performing

secondary insert injection molding according to performance and use of the product to treat the surface of the product to be smooth, and a method for manufacturing the same.

In order to achieve the above-described object of the invention, there is provided a compound iron and mineral material including a mineral rock and a fragment iron as essential elements, comprising 2 to 90wt% of a natural mineral rock and fragment iron having a specific gravity of 1.9 to 10.1 as essential elements, 8 to 10wt% of synthetic resin, and 2 to 5wt% of adhesives and additives.

There is also provided a method for manufacturing a compound iron and mineral material including a mineral rock and a fragment iron as essential elements, including the steps of: mixing a natural mineral rock, a fragment iron, a synthetic resin and additives ; heating a primary hot bin at a temperature from 160 to 300°C and transferring it ; dissolving a compound iron and mineral material, transferring the resultant material to a secondary vertical injection cylinder, preventing backflow, automatically measuring the material, and maintaining a temperature at 160 to 300°C ; and performing primary compression/injection molding on the mixed material in a mold.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 shows photographs of elements of a new material for manufacturing a compound iron and mineral material in accordance with the present invention, wherein Fig. la is a photograph showing a natural mineral rock and a fragment iron, Fig. lb is a photograph showing a mixed state of the natural mineral rock and fragment iron of Fig. la, and Fig. 1c is a photograph showing a synthetic resin; Fig. 2a is a photograph showing a primary compression/injection molding product in accordance with the present invention, and Fig. 2b is a photograph showing a secondary molding product (primary compression product is injection molded by using a plastic); and Fig. 3 is a flowchart showing sequential steps of a process for manufacturing a compound iron and mineral material in accordance with the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION A compound iron and mineral material including a mineral rock and a fragment iron as essential elements and a method for manufacturing the same in accordance with the present invention will now be described in detail with reference to the accompanying drawings.

In consideration of geological properties, a conventional method for manufacturing a balance weight material by refining a homogeneous mineral and a heterogeneous rock in an integrated iron and steel mill complicates the whole process and increases the production cost. In order to solve the foregoing problems, the present applicant made every effort to develop a new iron and mineral material of a natural mineral material, and succeeded in manufacturing the new material by mixing a few mineral rocks (natural mineral rock and fragment iron), and mixing the resultant material with various synthetic resins and additives.

The new iron and mineral material which can be easily processed and economically advantageous is manufactured by performing primary molding (compression/injection molding) according to properties, formation factors, performance, shape, chemical properties, physical properties and yield status of the mineral material, and performing secondary insert molding (product insert process general plastic molding for coating the surface with plastic) according to performance and use of the product. The new material can be appropriately used for various mechanical components, especially balance weights according to a predetermined process.

Things that should be considered to obtain a material suitable for a

kind and use of the product before processing the new material for balance weight will now be described.

In accordance with the present invention, the natural mineral rock and fragment iron are separately used or mixed. Therefore, one of them is determined as the essential element of the iron and mineral material.

Whether the materials are separately used or mixed is decided, and then a molding method of the materials is determined. Exemplary molding methods include press molding, injection molding and compression molding.

A mixing ratio of the materials is determined according to use of the product or wanted specific gravity. As shown in Table 1, the mixing ratio of the natural mineral rock and fragment iron having a specific gravity of 1.9 to 10.1, synthetic resin and additives can be varied to manufacture the new material.

[Table 1] No Natural mineral Fragment iron Synthetic resin Adhesives and rock additives 1 85-90 0-2 8-10 2-5 2 65-70 15-20 8-10 2-5 3 0-2 85-90 8-10 2-5

Here, the kind and content of the synthetic resin and additives can be varied according to whether the material is a power or liquid type, and determined on the basis of a mixing ratio and mixing type (for example, mixing or water spreading type) of the material.

Fig. 1 illustrates power type materials. In detail, Fig. la shows the natural mineral rock and fragment iron which are not mixed, Fig. lb shows the natural mineral rock and fragment iron mixed at the second ratio of Table 1 (70wt% of natural mineral rock and 20wt% of fragment iron), and Fig. Ic shows a powdered synthetic resin such as polyethylene and powdered additives such as antioxidants, thermal stabilizers, resin dispersing agents, resin lubricants and coloring additives.

A heating temperature of a primary hot bin is determined between 160 to 300°C according to the kind of the synthetic resin, and a cooling method for a mold is determined. Here, exemplary cooling methods include a direct cooling method and an indirect cooling method, which influence productivity.

Primary compression/injection molding is determined according to the shape or use of the product, and then secondary insert injection molding is determined. A re-heating process of the mold is determined. As

a result, it is possible to manufacture the compound iron and mineral material for balance weight which prevents the product or device from getting rusty and being decolorized, smoothes the surface, increases the specific gravity weight, reduces environmental contamination and lowers the production cost.

Fig. 2 illustrates a balance weight in accordance with the present invention. In detail, Fig. 2a shows a primary compression/injection molding product, and Fig. 2b shows a secondary injection molding product surface-treated by using a plastic.

When the material and production method have been determined, the product is manufactured according to the process of Fig. 3. However, a heating temperature of the primary hot bin and a temperature of the mold can be varied according to kinds of additives.

The natural mineral rock, fragment iron and synthetic resin are mixed at a ratio of Table 1 (compound iron and mineral material; S10).

Thereafter, the primary hot bin (material mixture, material dissolving, material transferring, cylinder heating, etc. ) is heated at a predetermined temperature (S20). Here, when the adhesives and additives are mixed with the synthetic resin (adhesive I), the primary hot bin is heated at a temperature from 160 to 300°C, and when the adhesives, synthetic resin

starch syrup (molasses) and ASCON are mixed (Prime coating, Tack coating, MC-1, RSC-T or AP) (adhesive II), the primary hot bin is heated at a temperature from 160 to 190°C.

The mixed compound iron and mineral material is transferred and re-heated. Preferably, in the case of adhesive I, the temperature is maintained similarly or identically to the temperature of the primary hot bin (160 to 300°C), and when the adhesive is ASCON (adhesive 11), the temperature is maintained at about 200°C.

The compound iron and mineral material mixed, transferred and put in a secondary compression cylinder is measured, and backflow of the material is prevented in S30. The material is compression/injection molded and completed as shown in Fig. 2a (S40). Here, when the synthetic resin (adhesive I) is employed as the adhesive, the product can be completed merely by performing the primary compression/injection molding according to its surface shape.

In S50, the compression molding product is cooled in the mold, and a temperature of the mold is preferably maintained at 140°C during the cooling process. Thereafter, the product is taken out of the mold (S60), passed through a cooling tunnel, and transferred to an insert injection molder for secondary injection (S70).

The product is insert molded according to the secondary injection molding (S80), and completed as shown in Fig. 2b (S90).

As described above, when adhesive I (namely, plastic adhesive) is used, the product can be completed merely by performing the primary compression/injection molding according to the surface asperity. However, when adhesive II (namely, starch syrup or ASCON) and the additives are used, the primary compression and the secondary injection molding must be performed to manufacture the product.

The natural mineral rocks, fragment irons, synthetic resins and adhesives which can be used for the present invention will now be listed.

The mineral rocks having a high specific gravity (for example, 1.9 to 10.1) are used as the natural mineral materials: 1) Metallic element mineral rocks (1) Native gold: quartz rock having specific gravity (G) of 16 to 19.3 2 Native silver: Nickel rock, cobalt rock, acanthite, stephanite, pyrargyrite and damask having G of 10.1 to 11.1 03 Native copper: chalcopyrite, bornite, chalcocite, enargite, malachite, azurite and cuprite having G of 8.5 to 8.9 (3) Native platinum: ultrabasic igneous rock, dunite and antigorite having G of 14 to 19 (pure one: 21.45)

(5) Native iron: ferromagnetic material having G of 7.5 to 7.8 (divided into ground iron and iron meteorite), such as magnetite, hematite, limonite and pyrite 2) Semi-metallic element mineral rocks # Native arsenic: proustite, realgar, orpiment, sphalerite and enargite having G of 5.7 (2) Native antimony: antimonite, senarmontite, valentinite and kernesite having G of 6.6 to 6.7 (S) Native bismuth: bismuthinite, tetradymite, bismite and bismutite having G of 9.7 to 9.8 3) Sulfides (D Acanthite (Ag2S): G of 7.2 to 7.3 (2) Galena (PbS): G of 7.4 to 7.6, blue lead has G of 11.4 (3) Niccolit (NiAs): millerite, pentlandite and nickel rock having G of 7.3 to 7.7 (A) Cinnabar (HgS): G of 8 (5) Realagar (As4S4) (B) Orpiment (As2S3) @) Stibnite (Sb2S3) (S Bismuthinite (Bi2S3): MoS2, CoAsS

# Others : argenopyrite (FeAsS), pyrargyrite (Ag3SbS3), Proustite (Ag3AsS3), Enargite (Cu3AsS4), Pyrite (FeS2), Greenockite (CdS) 4) Halogen mineral rocks (D Cerargyrite (AgCl) # Bromyrite (AgBr) 5) Oxide and hydroxide mineral rocks # Cuprite (Cu2O) (2) Zincite (ZnO) 3+ Magnetite (Fe 2<BR> <BR> <BR> <BR> <BR> <BR> <BR> <BR> # Hematite(Fe2O3) (5) Limonite (4 [FeO (OH) )) (ß) Ilmenite (FeTiO3) Q) Rutile (TiO2) # Uuraninite (UO@) # Pyrolusite(MnO2), Janggunite @ Monganite (MnO (OH) ) @ Psilomelane (2 [ (Ba#Mn2+) Mn44+O8(OH)2]) 0 Chromite (FeCr204) # Cassiterite (no2) S) Diaspore (4 [AIO (OH) ))

# Corundum (Al2O3) 6) Carbonate, nitrates and borates mineral rocks 1. Carbonate mineral calcites groups A. Calcite group (1) Calcite(CoCO3) (2) Magnesite (MgC03) (3) Slderite (FeCO3) @ Rhodochrosite(MnCO3) (S) Smithsonite (ZnCo3) B. Aragonite group (1) Aragonite (CaCo3) # Witherite (BaCo3) # Strontianite (SrCo3) C. Malachite (Cu2Co3- (OH) 2) D. Azurite (Cu3 (Co3) 2 (OH) 2) 2. Nitrates mineral rocks (D Sadaniter, Chile Saltpeter (NaN03) (2) Niter (KN03) 7) Sulfate, tungstates and molybdates mineral rocks 1. Sulfate mineral rocks

# Barite (BaS04) (2) Celestite (SrS04) # Anglesite (PbS04) 2. Tungstates mineral rocks # Wolframite ( (Fe#Mn)#WO4) # Scheelite (CaW04) 3. Molybdates mineral rocks # Wulfenite (PbMo04) 8) Phosphate and Native salt mineral rocks 1. Phosphate mineral rocks # Monazite (Ce, La, Y, Th) P04) (2) Apatite (Ca5 (F, Cl, OH) (PO4) 3) # Pyromorphite (Pb5 (P04) 3Cl) 2. Native salt mineral rocks # Erythrite(Co3(AsO4)2, 8H20) 9) Silicate minerals # Fayalite ( (Fa) : Fe2SiO4) (D Willemite (Zn2SiO4) # Zircon (ZrSi04) @ Thorite (ThSi04)

10) Fuel and organic substance minerals, and other mineral rocks Identically to the natural mineral materials, fragment irons having a specific gravity of 1.9 to 10. 1 are used.

Synthetic resins used at about 10wt% will now be listed.

1) Thermoplastic synthetic resins 1. Polyethylene # Low density polyethylene (LDPE: LUTENE) (2) Linear low density polyethylene (LLDPE: LUTENE-L) (3) Very low density polyethylene (VLDPE: RUFLEX) (3) High density polyethylene (HDPE-LUTENE-H, crosslinked polyethylene pipe LUTENE-H ? ? XL-PIPE1800) oxo Polyethylene compound for electric wire 2. Unsaturated polyester resins # Resin molding for FRP: resin for general lamination, resin for sunlight, resin for ship, resin for general molding, resin for filament winding, resin for SMC and BMC, resin for RTM, resin for matched die, corrosion resistant resin (corrosion resistant FRP), resin for mold, fire retardant resin (2) Resin molding for NON-FRP: resin for marble (3) Resin molding for coating: resin for film coating, resin for musical

instrument, resin for molding T Resin molding for gel coating: gel coating for FRP, gel coating for Non FRP (5) Hardening accelerators Hardeners (Z) Other additives 3. Other synthetic resins 2) Thermosetting synthetic resins The following adhesives are used according to properties of the product.

In addition to the synthetic resin adhesives, a starch syrup (molasses, malt syrup, liquid or solid material), Prime coating=MC- : slow hardening AP, and Tack coating=MSC-4: rapid hardening AP are used.

The following additives are used according to properties of the product.

An antioxidant for preventing the product or material from getting rusty, a thermal stabilizer for preventing the resin from being decolorized or discolored due to a high temperature, and a resin dispersing agent for evenly mixing the iron and mineral material, fragment iron or resin are used. On the other hand, when the compound iron and mineral material is

used at a high temperature, some times it does not smoothly flow into the transfer cylinder or mold. In order to facilitate flows of the material, stearic acid, namely a candle lump is molten and added, and a coloring additive for varying the shape or color of the product and sucrose are added.

The method for manufacturing the balance weight by using the natural mineral rock, fragment iron, synthetic resin and additives in accordance with the present invention will be better understood by referring to following examples.

Example 1 70wt% of natural mineral rock including 5wt% of native silver, 15wt% of native arsenic, 30wt% of acanthite and 20wt% of cuprite and 20wt% of fragment iron were put and mixed in the hopper, and 8wt% of polyethylene resin and 2wt% of plastic resin and additive which were an adhesive and additive were added to the resultant material, to generate a mixed material. The mixed material was put in the primary hot bin and heated at a temperature from 160 to 300°C (preferably 250°C). While the temperature was maintained, the mixed and dissolved material was transferred to the secondary vertical compression injection cylinder and automatically measured, and backflow of the material to the primary hot bin was prevented. The material was compression/injection molded in the

mold maintained at a temperature from 160 to 300°C (preferably 250°C), to obtain the product of Fig. 2a. The product was taken out of the mold, indirectly cooled through the cooling tunnel, and transferred to the injection molder for secondary insert molding by using a truck heaping apparatus. The product of Fig. 2b was obtained according to the insert molding.

Example 2 90wt% of mixed fragment iron including iron powder and 8wt% of polypropylene resin and additive were mixed, 2wt% of molasses which was an adhesive was added, and the resultant material was put and mixed in the hopper, to obtain the mixed mineral material. The mixed material was put in the primary hot bin and heated at a temperature from 160 to 300°C (preferably 250°C). While the temperature was maintained, the mixed material was transferred to the secondary vertical compression injection cylinder and automatically measured, and backflow of the material to the primary hot bin was prevented. The new material was compression/injection molded in the mold maintained at a temperature from 160 to 300°C (preferably 250°C), to obtain the product of Fig. 2a. The product was taken out of the mold, indirectly cooled through the cooling tunnel, and transferred to the injection molder for secondary insert

molding by using a truck heaping apparatus. The product of Fig. 2b was obtained according to the insert molding.

The balance weight must satisfy the environmental test standards.

Exemplary environmental tests include unit tests such as a specific gravity test, a heat resistance test, a cold and wet resistance test, a chemical resistance test, a sulfuric acid test and a weather resistance test, strength tests such as a breaking strength test and an impact test, and a product mounting test.

Although the new material for balance weight was exemplified, it should be recognized that the new material including the mineral rock and fragment iron as essential elements and also including the synthetic resin and adhesive could be applied to an electricity insulating material and a winter sowing preventing material such as a pump.

INDUSTRIAL APPLICABILITY As described above, the compound iron and mineral material including the natural mineral rock and fragment iron as essential elements and also including the synthetic resin can be manufactured at a low cost and simplify the whole manufacturing process.