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of Mines Research Institute, Duval Corp, C.F. &I. Steel
Corporation, and Climax Molybdenum Company, to list
some.
Bond was honored with the SME Richards Award at
their annual meeting in January, 1965. The citation on the
award read “For major contributions to increased knowl-
edge of crushing and grinding processes and for indus-
trial application of this knowledge to advancement of the
milling industry.” In his acceptance speech, he reminisced
about early experiences, from Northern Canada to the
Andes mountains. He noted that the industry still prac-
tices methods that are near primitive in terms of “squeezing
and chipping” to break rock. And finally, he criticized the
then current scientific community for lack of concern for
applied practicality (Mining Engineering, 1965, Apr., p.96).
Bond’s retirement writing can be classified into three
main categories. He wrote a monthly column for Rock
Products from 1965 to 1970. He also published a few (three)
journal articles. Finally, he contributed to SME’s Mineral
Processing Handbook, which was published in 1985, eight
years after his death.
Starting in June of 1965, Bond contributed a monthly
column for Rock Products entitled “On Line: An expert looks
at the care and nourishment of processing equipment.” The
topics varied widely through fifty-seven installments, con-
tinuing into 1970. The first addressed plant layouts, in par-
ticular allowing ample room for clean-up and maintenance
and the possibility of future expansion. Another talked of
the history of comminution equipment, from the arrastra (a
large grooved stone around which animals dragged a rock)
to modern crushers. The history of tumbling mills, that of
autogenous grinding, Bond’s Third Theory following those
of Kick and Rittinger, the work index equation, and metal
wear in crushing and grinding, all taken from previous
work, were covered in the tightly packaged snippets. Bond
spoke of the challenges and benefits of technical writing,
the nature of consulting work, and pursuit of excellence in
one’s field. His second-last was a discussion of parallels in
the lives of Isaac Newton and Albert Einstein. While add-
ing no significant technical knowledge, being addressed to
aggregate plant operators, he explained things very clearly,
but without simplification. Every article was titled only by
the name of the column mentioned above, but a full list
of each of the topics he addressed is provided in Appendix
B. These articles were reprinted, with the publisher’s per-
mission, in different order and to a reduced extent, in the
British Cement, Lime and Gravel, out of London, starting
in 1970, and subsequently in Cantreras y Explotaciones, out
of Madrid.
In June, 1967, Bond published “Autogenous Grinding
Evolution” in Mining Congress Journal. He pointed out the
earliest “autogenous” mills used pieces of the ore to replace
Danish pebbles in fine grinding tube mills. He made the
corrections to the history noted above, which may have
driven the desire to write this paper. He distinguished the
new approach of “primary autogenous grinding” from the
former, and the use of steel media added to create “semi-
autogenous,” or “ersatz autogenous” grinding, as he said it
should be properly named as an inferior or compromise
approach. He also described “intermediate (or “selective”)
autogenous grinding,” in which coarse material (say, plus
3") is screened off as media, the remaining material is stage
crushed (to, say, minus ½”), and then the two are com-
bined to grind autogenously. He also re-emphasized that
“True autogenous wet grinding will find more application
when the importance of maintaining a low pulp level in the
mill is realized.” Separately, he blamed the need to add steel
grinding media to a mill intended to operate fully autoge-
nously on a high slurry level in the mill, and recommended
in a letter (1966) to Allis-Chalmers that they develop a
peripheral discharge.
In December, 1967, Bond published “A New Look
at the Old Problem of Separator Performance” in Rock
Products magazine. He repeats his “separating size” formu-
lation from “Crushing and Grinding Calculations” (1961),
which he defines as the size which the cumulative percent
passing in the undersize equals the cumulative percent
retained in the oversize. He then provides two-product for-
mulae for calculation of circulating load ratio for forward
and reverse closed grinding circuits, and added those for
“sharpness of separation” and “separator efficiency.” He sug-
gests that these values can be used to quantify and thus
compare performances of plant separators. (Author’s note:
However, soon size by size recoveries to oversize and bypass
fraction were becoming standard separator performance
characterization tools, rendering Bond’s, and others’ similar
approaches, moot.)
On the request of the editor, Bond contributed
“Crushing and Grinding—There Should be a Better Way”
to the January, 1968, issue of Mining Engineering. This was
part of a broader article on industry long-term research
and development needs. He pointed out that 95–99% of
compression energy ends up as heat, and then speculated
on different “non-pressure” methods of breakage that may
hold promise for the future through research and develop-
ment. These were centrifugal force induced vibration high
voltage underwater discharge induction heating water or
steam injection lasers and penetration with an ultra-hard
sharp point. He noted equipment size growth, and the need
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