Peter Ritter von Rittinger was an outstanding mineral scientist whose equipment inventions and mathematical descriptions of unit operations established mineral processing as a modern technology (Steiner 2000; Vozar and Kunnert 1972). He was the first to provide a sound mathematical basis for the physics of wet classification and gravity separation processes, and the first to discuss the quantitative relationship between the energy consumed and the size reduction achieved in crushing and grinding.
Von Rittinger was born in 1811 in Neutitschein/Mahren, Austria, to parents who died when he was very young. His education was financed by scholarships. After studying philosophy and jurisprudence at the University of Olmutz, Austria, he went to the Austrian Mining Academy in Schemnitz, where he graduated with honors as a mining engineer in 1839. He then worked in various capacities with state-owned mining enterprises. He was assigned to supervise and modernize mineral processing plants, which in those days were mainly based on grinding and gravity separation circuits. Separation processes of the time were batch rather than continuous, and von Rittinger saw the need for change. His first two inventions were the Spitzkasten, which enabled classification of fine particles ahead of gravity concentration, and the continuous shaking table, which was the basis of the later and more successful Wilfley table.
In those days mining engineering included mining and mineral processing, and von Rittinger moved around the industry, taking on a variety of tasks in both areas. Selected highlights of his career included serving as a coal exploration officer at Brandeisel, where he was responsible for the rapid sinking of two shafts; managing mining at Joachimsthal, where he designed the deepest shaft of the time; designing ventilators for mines, a concept that was used for 60 years; and inventing the thermocompression process for the evaporation of water from salt brines.
Von Rittinger earned a worldwide reputation as an outstanding scientist when he published a comprehensive textbook on mineral processing (Lehrbuch der Aufbereitung — skunde; von Rittinger 1867). The book described equipment and processes, and was accompanied by two heavy volumes of beautiful lithographic drawings of all the technical equipment that operated in mineral processing plants at the time. But his book went much further than describing machines and processes. He recognized the importance of quantitatively explaining the principles involved in the processes, using equations to do so. Between his inventions and his outstanding textbook, it is not surprising that von Rit — tinger is regarded as the man who laid the foundation for today’s mineral processing technology. His achievements were of such stature that he was awarded civic as well as technical honors, including being ennobled by the state.
In discussing size reduction in his textbook, von Rittinger commented that “The throughput (of wet operated stamp mills) is proportional to the 0.4 power of the linear dimension of the openings of the discharge screen.” This type of empirical relationship, which was unusual at the time, was similar to the later Bond equation. To clarify, he used an analogy of making estimates of the new surface produced by repeated breakage of particles into smaller particles. Although his original equation was correct, the analogy suffered the fate of many simplifications when other authors took it to be an actual hypothesis (Steiner 2002). Eventually the energy-size reduction relationship attributed to von Rittinger came to be stated in this way: “The work done in crushing is proportional to the area of new surface produced” (i. e., proportional to the reduction in linear dimension; Richards and Locke 1940). The hypothesis attributed to von Rittinger is defined by the equation E = kd[ 1 /x2 — 1 /x1 ], where E is the energy, k is a constant, and x1 and x2 are the feed and product sizes. These symbols have the same meaning for the Kick and Bond equations.