Lithia is the oxide of lithium, (LiO2), usually added to ceramic batches by means of chemically prepared lithium compounds.
Lithia is a very powerful flux, especially when used in conjunction with potash and soda feldspars. It is a valuable component in glasses having a low thermal expansion where its use permits the total alkali content to be kept to a minimum. The low thermal expansion properties also are exploited in flameproof ceramic bodies and glass ceramics where the formation of beta spodumene is the basis for oven-to-tableware production. It also enables the production of certain glasses having high electrical resistance and desirable working properties. A relatively high content of lithia allows the production of glasses that transmit ultraviolet light.
Glasses containing lithia are much more fluid in the molten state than those containing proportional amounts of sodium or potassium, and the successful use of lithia in glassmaking lies in the fact that much smaller amounts are required to produce a glass of the necessary fluidity for working without sacrificing the desired physical and chemical properties. In addition, lithia is being utilized to increase furnace capacity, decrease melting temperatures, and increase production capacities.
Uses
Although lithium batteries boast the highest energy density of any rechargeable, cobalt in the cathode keeps cost high — a lithium battery for an electric vehicle costs about $20,000. Computer modeling predicts a less expensive replacement material. Follow-on tests verify that a cathode made from a mixture of lithium aluminum oxide and lithium cobalt oxide could not only decrease battery cost by a significant margin, but also increase cell voltage.
Aluminum-lithium alloys are basically 2XXX and 7XXX aluminum alloys containing up to about 3% lithium. Because of the extremely light weight of lithium, they provide higher stiffness-to-density ratios than traditional structural aluminum alloys and, thus, have potential for aircraft applications. Because of the low weight, lithium compounds give the highest content of hydrogen, oxygen, or chlorine. Lithium hydride, LiH, a white or gray powder, is used for the production of hydrogen for signal balloons and floats. Lithium aluminum hydride, or lithium alanate, LiA1H4, is used in the chemical industry for one-step reduction of esters without heat. Lithium metal is very sensitive to light, and is also used in light-sensitive cells.
Lithium is soluble in most commercial metals only to a slight extent: it is a powerful deoxidizer and desulfurizer of steel, but no lithium is left in the lithium-treated steel. In stainless steels it increases fluidity to produce dense castings. Cast iron treated with lithium has a fine grain structure and increased density with high impact value. Not more than 0.01% remains in the casting when treated with lithium-copper. In magnesium alloys the tensile strength is increased greatly by the addition of 0.05% lithium.
Lithium copper is a high conductivity, high-density copper containing a minute quantity of residual lithium, 0.005 to 0.008%, made by treating copper with a lithium-calcium-master alloy.
Lithia has been widely used in the production of pottery glazes of high quality. The addition of 1% lithium carbonate in the frit or the fluoride or silicate in the mill to dinnerware, electrical porcelain, and sanitary ware glazes has been found to increase the resulting gloss to a marked degree.
