ORE, a mineral body, partly or entirely composed
of metallic substances, in the natural state in which it exists in the earth. Metallic substances are found, either native, that is, pure, and uncombined with other substances, or alloyed with other metals, or combined with oxygen, or sulphur, or with acids; and thus it appears, that metals exist in ores, in four different states. 1. In the metallic state, when they are either pure, or combined with each other, as in the state of alloy. 2. In the state of an oxide. 3. Combined with sulphur in the state of sulphuret. And, 4. with acids, forming salts. For the particular description of ores, see MINERALOGY; and for the mode of their distribution in the earth, see GEOLOGY.
But ores are rarely found exactly in the state of combination now mentioned. It seldom indeed happens, that they are not mixed with various earthy minerals. As all metals are extracted from ores, it is of great importance to be acquainted, in the first place, with the materials of which they are composed, as they are obtained from the earth, with the view of ascertaining the nature and proportions of the various ingredients which enter into the composition; and in the second place, to know the simplest and easiest processes by which the metals may be separated, for the purposes of economy and manufacture. Hence, in the treatment of ores, two objects are in view. The first is their analysis, which is the province of the chemical philosopher; and the second is their reduction in the large way, which is the business of the metallurgist. The most improved methods for accomplishing each of these objects, will be detailed in the following treatise.
IN the treatment of metallic ores, it has been already hinted, that two objects are in view: the one is to obtain a knowledge of the nature and proportions of their component parts; and the other is to be acquainted with the best methods of separating the metals which they contain, that they may be applied in their pure or uncombined state to useful purposes. In the following treatise, therefore, we shall keep in view the same objects: and under each of the metals we shall first detail the most improved methods of analysing its different ores; and, secondly, give a short account of the best and most approved processes that are employed in their reduction. The last object, however, refers only to some of the metals, others not being found in sufficient quantity, or not being applicable to useful purposes.
In this treatise we shall consider the metals in the same order in which they have been described under MINERALOGY, and to each metal we shall devote a particular chapter.