إلْمـِنيت Ilmenite معدن أسود ثقيل، هجريبه الكيميائي FeTiO3 ، ويُطلق عليه أيضاً خام الحديد التيتاني. وهومهم، لأنه مصدر لمادة التيتانيوم. ويتم تكوينه في درجات الحرارة العالية. ويحتوي على 36,8% من الحديد و31,6% تيتانيوم. وتعوق الصعوبات التي تعترض صهر الإيلمنيت انتشار استعماله حديداً خاماً. ويُستخرج الإيلمنيت من مناجم الولايات المتحدة وروسيا والنرويج وكندا.

البنية والخصائص

يتبلور الإلمنيت في نظام ثلاثي الأضلاع. البنية البلورية للإلمنيت consists of an ordered derivative of the corundum structure; in corundum all cations are identical but in ilmenite Fe²⁺ and Ti⁴⁺ ions occupy alternating layers perpendicular to the trigonal c axis. Containing high spin ferrous centers, ilmenite is paramagnetic.

Ilmenite is commonly recognized in altered igneous rocks by the presence of a white alteration product, the pseudo-mineral leucoxene. Often ilmenites are rimmed with leucoxene, which allows ilmenite to be distinguished from magnetite and other iron-titanium oxides. The example shown in the image at right is typical of leucoxene-rimmed ilmenite.

In reflected light it may be distinguished from magnetite by more pronounced reflection pleochroism and a brown-pink tinge.

Samples of ilmenite exhibit a weak response to a hand magnet.

الاكتشاف

في 1791، اكتشف وليام گريگور الإلمنيت، في غدير ينساب عبر وادي جنوب قرية مناكان (كورنوال)، وتعهد لأول مرة التيتانيوم كأحد مكونات الإلمنيت.

الكيمياء المعدنية

Paragenesis

Ilmenite is a common accessory mineral found in metamorphic and igneous rocks. It is found in large concentrations in layered intrusions where it forms as part of a cumulate layer within the silicate stratigraphy of the intrusion. Ilmenite generally occurs within the pyroxenitic portion of such intrusions (the 'pyroxene-in' level).

Magnesian ilmenite is indicative of kimberlitic paragenesis and forms part of the MARID association of minerals (mica-amphibole-rutile-ilmenite-diopside) assemblage of glimmerite xenoliths. Manganiferous ilmenite is found in granitic rocks and also in carbonatite intrusions where it may also contain anomalous niobium.

Many mafic igneous rocks contain grains of intergrown magnetite and ilmenite, formed by the oxidation of ulvospinel. Ilmenite also occurs as discrete grains, typically with some hematite in solid solution, and complete solid solution exists between the two minerals at temperatures above about 950 °C.

التيتانيوم تعهد عليه لأول مرة وليام گريگور في 1791 في الإلمنيت من وادي مناكان في كورنوال، بجنوب غرب إنگلترة.

وقد أخذ الإلمنيت اسمه من مكان اكتشافه في جبال إلمنسكي، بالقرب من مياس، روسيا.

الاستهلاك

المعالجة والاستهلاك

Most ilmenite is mined for titanium dioxide production. In 2011, about 47% of the titanium dioxide produced worldwide were based on this material. Finely ground titanium dioxide is a bright white powder widely used as a base pigment in paint, paper and plastics. Metallic Titanium can be easily derived from it for uses such as aircraft and high-strength steel devices.

North America and Europe together consume about 50% of the world's titanium dioxide production. Demand by India and China is growing rapidly and may eventually surpass Western consumption.

السبائك

Ilmenite is an ingredient in the manufacture of the ferrotitanium and ferro-carbon-titaniumalloys.

الانتاج

في يوليو2018، بلغ ثمن الطن من الإلمنيت 170 دولار. وإذا تم صهره ليصبح روتيل يقفز ثمنه إلى 1,250 دولار للطن.

Australia was the world's largest ilmenite ore producer in 2011, with about 1.3 million tonnes of production, followed by South Africa, Canada, Mozambique, India, China, Vietnam, Ukraine, Norway, Madagascar and United States.

Although most ilmenite is recovered from heavy mineral sands ore deposits, ilmenite can also be recovered from layered intrusive sources or "hard rock" titanium ore sources.

The top four ilmenite and rutile feedstock producers in 2010 were Rio Tinto Group, Iluka Resources, Exxaro and Kenmare Resources, which collectively accounted for more than 60% of world's supplies.

The world's two largest open cast ilmenite mines are:

• The Tellnes mine located in Sokndal, Norway, and run by Titania AS (owned by Kronos Worldwide Inc.) with 0.55 Mtpa capacity and 57 Mt contained TiO 2 reserves.
• The Rio Tinto Group's Lac Tio mine located near Havre Saint-Pierre, Quebec in Canada with a ثلاثة Mtpa capacity and 52 Mt reserves.

Major mineral sands based ilmenite mining operations include:

• Richards Bay Minerals in South Africa, majority-owned by the Rio Tinto Group.
• Kenmare Resources' Moma mine in Mozambique.
• Iluka Resources' mining operations in Australia including Murray Basin, Eneabba and Capel.
• The Kerala Minerals & Metals Ltd (KMML), Indian Rare Earths (IRE), VV Mineral mines in India.
• TiZir Ltd.'s Grande Cote mine in Senegal
• QIT Madagascar Minerals mine, majority-owned by the Rio Tinto Group, which began production in 2009 and is expected to produce 0.75 Mtpa of ilmenite, potentially expanding to 2 Mtpa in future phases.

Attractive major potential ilmenite deposits include:

• The Karhujupukka magnetite-ilmenite deposit in Kolari, northern Finland with aroundخمسة Mt reserves and ore containing about 6.2% titanium.
• The Balla Balla magnetite-iron-titanium-vanadium ore deposit in the Pilbara of Western Australia, which contains 456 million tonnes of cumulate ore horizon grading 45% Fe, 13.7% TiO 2 and 0.64% V 2O 5, one of the richest magnetite-ilmenite ore bodies in Australia
• The Coburn, WIM 50, Douglas, Pooncarie mineral sands deposits in Australia.
• The Magpie titano-magnetite (iron-titanium-vanadium-chrome) deposits in eastern Quebec of Canada with about 1 billion tonnes containing about 43% Fe, 12% TiO2, 0.4% V2O5, and 2.2% Cr2O3.
• The Longnose deposit in Northeast Minnesota is considered to be "the largest and richest ilmenite deposit in North America."

الإلمنيت القمري

عـُثر على الإلمنيت في صخور القمر، وهوغني بالمغنسيوم مثل الرابطة الكمبرليتية. وفي 2005 استخدمت ناسا تلكسوب الفضاء هبل لتحديد المواقع الغنية بالإلمنيت. وقد يحدث هذا المعدن فائق الأهمية لأي قاعدة قمرية محتملة، إذ حتى الإلمنيت سيكون مصدراً للحديد والتيتانيوم لبناء المنشآت ولاستخلاص الأكسجين.

الإلمنيت في مصر

The Egyptian magmatic ilmenite is classified as a medium-grade ore. The present work is an attempt to produce a high-quality TiO2 that can be used in several industries from this medium-grade raw material using the mechanical activation, carbothermic reduction, hydrochloric acid leaching and calcination. A mixture from the ilmenite (FeTiO3) and activated carbon was milled for 30 h. This mixture was annealed at 1200 °C for one hour and the product was leached by hydrochloric acid and calcined at 600 °C for two hours. The role of the ball milling was to grind the raw ilmenite to obtain the nano size, and the carbothermic reduction was to reduce all the Fe-Ti phases to a mixture from Fe metal and TiO2. Leaching procedure was carried out to remove all the Fe metal and obtain a high-grade TiO2. After leaching and calcination of the milled and annealed mixture of FeTiO3/C under the optimal conditions, TiO2 nanoparticles with a size of 10–100 nm and purity more than 95% were obtained. The qualifications of the synthesized high purity rutile nanoparticles from the Egyptian natural ilmenite match the conditions of many industrial applications.

الخام

رواسب أكاسيد Fe-Ti الصهارية Magmatic في مصر تتواجد في جنوب الصحراء الشرقية. Among these deposits, there are considerable reserves من خام الإلمنيت في منطقة أبوغلقة. The estimations of the إحتياطيات خام الإلمنيت في منطقة أبوغلقة متغيرة، يتراوح من ثلاثة مليون طن (Holman، 1956)، إلىعشرة مليون طن (محرم، 1959) إلى 50 مليون طن (محمود ورفاقه، 2004).

خامات إلمنيت أبوغلقة ينكن تصنيفها إلى خام أسود (طازج) وخام أحمر (مؤكسد) ولكن التجارب أُجريت على الخام الأسود لأنه يشكل أغلبية الاحتياطي في منجم أبوغلقة المفتوح للإلمنيت.

المصادر

نطقب:Titanium minerals