14
for increased separator efficiency. Finally, he again expressed
his reservations about semi-autogenous grinding.
Bond’s final published technical writings were for the
SME’s Mineral Processing Handbook, which was published
in 1985. He participated early on (the early 1970’s) in the
planning of this major publication, and is acknowledged
for having done so in the list of editorial committee mem-
bers. However, he found it very difficult to act both as
a major writing contributor, as well as an editor, and so
resigned from the editorial committee to focus on the for-
mer. To this end he compiled eleven chapters covering all
the aspects of his grinding expertise.
Because he passed away in 1977, almost a decade
before its publication, Bond was not aware that only four
of his contributions were chosen for the final publica-
tion. Apparently frustrated with the pace of progress, in
November, 1976, Bond submitted the entirety of his eleven
chapters to Prof. W.A. Cunningham at the University of
Texas for the planned Encyclopedia of Chemical Processing
and Design. The responding request back to him for con-
densation of the materials was sent two months after Bond’s
death.
Section 3A of the Mineral Processing Handbook was on
“General Aspects of Comminution.” Bond wrote Ch. 5.
“Testing and Calculations.” He covers particle sizing, from
screen analyses, to options and difficulties in measuring size
analysis of fines. He provides the work index equation for
calculation of work required, and then a series of applicable
“ball mill efficiency adjustment factors.” Also similar to pre-
vious “Crushing and Grinding Calculations,” he provides
the equations for mill critical speed and recommended ball
sizing. He includes a table of ball mill diameter efficiency,
also related to mill speed, extended to 18’, which shows
increasing efficiency up to, but not including that size, at
which a drop in efficiency is shown. He reviews his equa-
tions for circulating load ratio and classifier performance,
followed by ball and rod mill grindability tests, and cal-
culation of work indices therefrom. He ends this section
with a description of the Allis-Chalmers abrasion test, and
its application to estimate steel wear rates in crushing and
grinding.
Section 3C was on “Grinding.” Within Ch. 4 on
“Autogenous Mills,” Bond wrote the “History of Autogenous
Grinding.” Here he reiterated much of his previous writ-
ing, from the earliest tube mills that replaced chert pebbles
with pieces of the ore, to the then growing trend towards
large diameter, secondary, semi-autogenous mills. He also
co-authored Ch. 8. “Other Grinding Machines” with K.J.
Edmiston and M.H. Kahn, covering a large variety of
grinding machines and methods outside of the usual ball,
rod and (semi-) autogenous tumbling mills. Besides roll-
ers, impactors and stirring devices, they briefly described
many unusual means of input energy into rock particles, as
examples vibration, high-speed attrition, supersonic sound
and high voltage electrical discharges.
But the most striking was what he wrote under “History,”
in section 3A on “General Aspects of Comminution,”
reserved as a final note in this biography as one of his most
important, albeit last, contributions to his legacy. He first
briefly covered methods and machinery, from man’s first
use of hammers, to the first jaw crusher, the first tube mills,
up to primary autogenous grinding and the large (18-foot
diameter) ball mills at the time (again, early 1970’s) of
writing. The next section described “Theoretical Issues,”
comparing the Kick and Rittinger theories, followed by
what he surprisingly termed the “Bond Compromise.” He
deemed the Work Index equation as “derived empirically as
the result of experimental testing,” and although “theoreti-
cally proportional to the length of crack-tips formed,” such
concept was “of little value because the length of crack-tips
formed is indeterminate except as the square root of new
surface area,” the latter also an assumption because such
surface area could not be measured. Bond thusly acknowl-
edged his Work Index relationship to be an empirical obser-
vation, and while highly useful, lacking proof in any theory.
His following brief discussion on the gross inefficiency of
compression breakage methods concludes with “Because
of widely distributed zones of low resistance, rock is not
homogeneous to breakage, and there is no basic theory of
comminution that can be generally accepted.”
Fred Bond died suddenly of an apparent heart aneu-
rism on January 23, 1977, in Tucson, Arizona. His wife,
Margaret Jean, died in 1988. They are buried at the Golden
Colorado cemetery.
BIBLIOGRAPHY/REFERENCES
(CHRONOLOGICALLY, WITHIN
GROUPINGS)
Autobiographical
Bond, Fred C., 1966, autobiographical notes.
Bond, F.C., 1975, It Happened to Me, 388 p. (also e-book
on Amazon.com (Kindle), BarnesNoble.com (Nook)
and Smashwords.com).
Referenced Books, Papers, Articles and Reports of
Others
Lennox, L.W., 1919, “Grinding Resistance of Various
Ores,” AIME Trans., v. 61, p. 237.
Anon., 1923, The Prospector, Annual of the Colorado School
of Mines, p.35.
for increased separator efficiency. Finally, he again expressed
his reservations about semi-autogenous grinding.
Bond’s final published technical writings were for the
SME’s Mineral Processing Handbook, which was published
in 1985. He participated early on (the early 1970’s) in the
planning of this major publication, and is acknowledged
for having done so in the list of editorial committee mem-
bers. However, he found it very difficult to act both as
a major writing contributor, as well as an editor, and so
resigned from the editorial committee to focus on the for-
mer. To this end he compiled eleven chapters covering all
the aspects of his grinding expertise.
Because he passed away in 1977, almost a decade
before its publication, Bond was not aware that only four
of his contributions were chosen for the final publica-
tion. Apparently frustrated with the pace of progress, in
November, 1976, Bond submitted the entirety of his eleven
chapters to Prof. W.A. Cunningham at the University of
Texas for the planned Encyclopedia of Chemical Processing
and Design. The responding request back to him for con-
densation of the materials was sent two months after Bond’s
death.
Section 3A of the Mineral Processing Handbook was on
“General Aspects of Comminution.” Bond wrote Ch. 5.
“Testing and Calculations.” He covers particle sizing, from
screen analyses, to options and difficulties in measuring size
analysis of fines. He provides the work index equation for
calculation of work required, and then a series of applicable
“ball mill efficiency adjustment factors.” Also similar to pre-
vious “Crushing and Grinding Calculations,” he provides
the equations for mill critical speed and recommended ball
sizing. He includes a table of ball mill diameter efficiency,
also related to mill speed, extended to 18’, which shows
increasing efficiency up to, but not including that size, at
which a drop in efficiency is shown. He reviews his equa-
tions for circulating load ratio and classifier performance,
followed by ball and rod mill grindability tests, and cal-
culation of work indices therefrom. He ends this section
with a description of the Allis-Chalmers abrasion test, and
its application to estimate steel wear rates in crushing and
grinding.
Section 3C was on “Grinding.” Within Ch. 4 on
“Autogenous Mills,” Bond wrote the “History of Autogenous
Grinding.” Here he reiterated much of his previous writ-
ing, from the earliest tube mills that replaced chert pebbles
with pieces of the ore, to the then growing trend towards
large diameter, secondary, semi-autogenous mills. He also
co-authored Ch. 8. “Other Grinding Machines” with K.J.
Edmiston and M.H. Kahn, covering a large variety of
grinding machines and methods outside of the usual ball,
rod and (semi-) autogenous tumbling mills. Besides roll-
ers, impactors and stirring devices, they briefly described
many unusual means of input energy into rock particles, as
examples vibration, high-speed attrition, supersonic sound
and high voltage electrical discharges.
But the most striking was what he wrote under “History,”
in section 3A on “General Aspects of Comminution,”
reserved as a final note in this biography as one of his most
important, albeit last, contributions to his legacy. He first
briefly covered methods and machinery, from man’s first
use of hammers, to the first jaw crusher, the first tube mills,
up to primary autogenous grinding and the large (18-foot
diameter) ball mills at the time (again, early 1970’s) of
writing. The next section described “Theoretical Issues,”
comparing the Kick and Rittinger theories, followed by
what he surprisingly termed the “Bond Compromise.” He
deemed the Work Index equation as “derived empirically as
the result of experimental testing,” and although “theoreti-
cally proportional to the length of crack-tips formed,” such
concept was “of little value because the length of crack-tips
formed is indeterminate except as the square root of new
surface area,” the latter also an assumption because such
surface area could not be measured. Bond thusly acknowl-
edged his Work Index relationship to be an empirical obser-
vation, and while highly useful, lacking proof in any theory.
His following brief discussion on the gross inefficiency of
compression breakage methods concludes with “Because
of widely distributed zones of low resistance, rock is not
homogeneous to breakage, and there is no basic theory of
comminution that can be generally accepted.”
Fred Bond died suddenly of an apparent heart aneu-
rism on January 23, 1977, in Tucson, Arizona. His wife,
Margaret Jean, died in 1988. They are buried at the Golden
Colorado cemetery.
BIBLIOGRAPHY/REFERENCES
(CHRONOLOGICALLY, WITHIN
GROUPINGS)
Autobiographical
Bond, Fred C., 1966, autobiographical notes.
Bond, F.C., 1975, It Happened to Me, 388 p. (also e-book
on Amazon.com (Kindle), BarnesNoble.com (Nook)
and Smashwords.com).
Referenced Books, Papers, Articles and Reports of
Others
Lennox, L.W., 1919, “Grinding Resistance of Various
Ores,” AIME Trans., v. 61, p. 237.
Anon., 1923, The Prospector, Annual of the Colorado School
of Mines, p.35.