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Iron haematite

Iron Haematite Iron(m) oxide Fe203 Heat oxide with carbon... [Pg.169]

Iron Haematite (Fe203) Reduce Fe203 with carbon monoxide... [Pg.79]

After aluminium, iron is the most abundant metal and the fourth most abundant of all the elements it occurs chiefly as oxides (for example haematite (FCjO,), magnetite (lodestonej (FC3O4) and as iron pyrites FeSj- Free iron is found in meteorites, and it is probable that primitive man used this source of iron for tools and weapons. The extraction of iron began several thousand years ago, and it is still the most important metal in everyday life because of its abundance and cheapness, and its ability to be cast, drawn and forged for a variety of uses. [Pg.391]

If an aqueous solution of an iron(lll) salt is treated with alkali, a red-brown precipitate of iron(III) hydroxide is obtained this is probably best represented as FeO(OH). On strong heating it gives the red oxide Fe203. Iron(III) oxide, Fc20, occurs naturally as haematite, and can also be prepared by strong heating of iron(II) sulphate ... [Pg.394]

The resultant slag, a complex mixture of titanates, may contain 70—85% Ti02- The slag route is particularly useful when ilmenite is closely associated with haematite, from which it cannot economically be separated mechanically. Because the iron content of the slag is low, its use reduces the quantity of iron sulfate in the Hquid effluent of sulfate process plants. Slag used as a feedstock for TiCl production must be low in magnesium and calcium. A variety of other ilmenite beneficiation or synthetic mtile processes have been pursued, primarily to provide alternative chloride process feedstocks. Low grade ilmenite... [Pg.123]

Odier metals having vety stable oxides can be reduced by the aluminothermic reaction to produce useful feno-alloys. Niobium oxide, NbO, can be reduced to form a feiTO-alloy by the inclusion of iron in die reacting iiiixmre as haematite or magnetite, depending on the niobium content which is requhed in the product. [Pg.344]

The furnace is charged with a mixture of the ore (usually haematite), coke and limestone, then a blast of hot air, or air with fuel oil, is blown in at the bottom. The coke bums and such intense heat is generated that temperatures approaching 2000°C are reached near the base of the furnace and perhaps 200°C at the top. The net result is that the ore is reduced to iron, and silicaceous gangue forms a slag (mainly CaSi03) with the limestone ... [Pg.1072]

Holding of the temperature between 400 and 575°C causes the iron particles to coagulate and the scale becomes further enriched in oxygen. Since wiistite is unstable below 575°C, scales produced at temperatures lower than this contain magnetite and haematite only. In addition, the scales are often cracked and porous. This is due to the difference in contraction... [Pg.290]

Oxides Metal ion(s) + oxygen ion Haematite (composed of iron oxide), a red pigment and an iron ore Corundum (composed of aluminum oxide), an abrasive silica (composed of silicon dioxide), common sand... [Pg.36]

Addition of sufficient base to give a > 3 to a ferric solution immediately leads to precipitation of a poorly ordered, amorphous, red-brown ferric hydroxide precipitate. This synthetic precipitate resembles the mineral ferrihydrite, and also shows some similarity to the iron oxyhydroxide core of ferritin (see Chapter 6). Ferrihydrite can be considered as the least stable but most reactive form of iron(III), the group name for amorphous phases with large specific surface areas (>340 m2 /g). We will discuss the transformation of ferrihydrite into other more-crystalline products such as goethite and haematite shortly, but we begin with some remarks concerning the biological distribution and structure of ferrihydrite (Jambor and Dutrizac, 1998). [Pg.52]

The reaction mechanism for the solid state reduction is the same as that described above for the hydrogen reduction of haematite, namely the formation of a porous iron product which results from the penetration of pores in the reacting pellets by reducing gases, and the migration of the reaction products, C02 and H20 through these pores back into the gaseous phase. [Pg.280]

In order to analyse the packed bed process, it is necessary to consider both heat transfer from the solid to the gas and reaction heat which may be transmitted to the gas. The composition of the gas, and hence its physical properties, are determined by the rate of reduction, which in turn depends on each layer of the packed bed, and on the degree of reduction which has already occurred. In the reduction of haematite, there are three stages in the reduction, corresponding to the formation of Fe304 and FeO before the metal is formed. The thermal data for the reduction processes can be approximated by the respective heats of reduction by H2 and CO gases. Taking 1000°C as a typical mean temperature, the mean value for the heats of reaction per 2 gram-atom of iron are... [Pg.280]

Goethite A process for removing iron from leach liquors from hydrometallurgical leaching operations. Used in recovering zinc from the residues of the electrolytic zinc process. See also Jarosite, Haematite. [Pg.116]

Jarosite [Named after the mineral, first recognized at Jarosa, Spain] A process for removing iron from the leach liquors from hydrometallurgical operations. First used in 1964 in processing zinc sulfate liquors at Asturiana de Zinc, Spain. Also used for recovering zinc from the residues from the electrolytic zinc process. See also Goethite, Haematite. [Pg.149]

Occurrence. Iron is highly abundant (about 5.5% of the earth s crust) it is believed that the core of earth is mostly molten iron together with nickel. The most common ore is haematite (Fe203). Iron is found in other minerals such as magnetite, limonite, siderite, pyrite. Iron is found native in meteorites known as siderites. [Pg.429]

The temperature at which the reduction by the hydrogen takes place varies with the different oxides and also with the same oxide, depending on its physical condition. " Crystalline haematite, as the naturaJ ferric oxide is called, requires to be at a red heat (about 500° C.) before reduction begins to tadce place, while if iron is precipitated from one of its salts (as ferric hydrate by... [Pg.18]

Acid leaching is usually carried out using sulfuric acid under pressure to dissolve the majority of the iron minerals and to release the cobalt and nickel. If this is carried out at 150-250°C, then the iron(III) is precipitated as haematite or jarosite, reducing the amount of iron in the leachate. The... [Pg.469]

Other types of cements include anhydrite, barite, pyrite, iron hydroxides haematite, albite and apatite and are subordinate. [Pg.379]


See other pages where Iron haematite is mentioned: [Pg.14]    [Pg.124]    [Pg.14]    [Pg.124]    [Pg.198]    [Pg.222]    [Pg.223]    [Pg.270]    [Pg.280]    [Pg.280]    [Pg.333]    [Pg.1071]    [Pg.1072]    [Pg.1080]    [Pg.26]    [Pg.967]    [Pg.291]    [Pg.293]    [Pg.34]    [Pg.513]    [Pg.53]    [Pg.54]    [Pg.270]    [Pg.333]    [Pg.157]    [Pg.451]    [Pg.126]    [Pg.9]   
See also in sourсe #XX -- [ Pg.366 ]




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