Back in August and December 2000 a couple of postings appeared relating
to the Elkington copper refining process and various plants built around the
world using that technology.  I dug up some information for other work and
offer it here in the hopes that it may still be of value.  I apologize if
much of this retraces steps already taken.
 There seem to be questions rather the Pembrey plant was ever built (it
was) and whether the first US plant was that built in 1892 for Nichols in
Laurel Hill, NY (it was not).
 Further, information based on primary sources was being sought.  As will
be seen in what follows, while the citations here are from secondary sources,
they are contemporary to development and application of the process and I've
found them to be completely reliable.  The various books also list specific
references that may have more particulars along the lines of primary archival
material.  Since many of the authors in this timeframe (late 1890's, early
1900's) visited the various plants they discuss, some of the data they
published could actually be considered primary in any case.  The authors
certainly had a wide acquaintance and correspondence within the industry.
    The Elkington side of the copper refining contribution (patents in 1865,
Pembrey, Wales plant in 1869) are discussed in Hofman's Metallurgy of Copper,
1st. edit. (1914), page 483-4.  Others may have looked in there already, but
checking his references is always worthwhile as they are more thorough than
other books of the era (equal or better even than Schnabel).  Hofman
discusses the first US application at the Balbach works in Newark, N.J.,
started in 1883.  This is of course contrary to the 1892 date (Nichols
Chemical Co, Laurel Hill, NY, see discussion below).  I can find no reference
to Mason.
    Ulke's Modern Electrolytic Copper Refining (1903), page 107-110 describes
the Balbach refinery in more thorough detail.  The Pembrey works are
described on page 115. Capacity is 130 t/week, 1065 vats were used (multiple
process) and 385 kw of power.  More data on current density and electrode
size is give in the rather brief description.  There seems no doubt the plant
existed.  Hofman's references on page 483 may have more specifics on the
Pembrey works.  I do not have Addicks copper refining book, he may have more
specifics as well.
    In any case, Ulke has very good descriptions of many plants around the
world, with discussions of the various approaches used, and should be used to
correct the coverage by Chadwick of early work in volume 5 of History of
Technology.  His section is mainly based on the AIME 1933 Rocky Mountain Fund
book on Copper Metallurgy.  The authors of the paper referenced in HOT worked
for Nichols, and contrary to what Chadwick has they do not say the first
application in the US was in 1892, only that Nichols started up their plant
in 1892.  The Nichols refinery is briefly described on page 99 of Ulke.
    Schnabel discusses Elkington in Volume 1, page 341, has the Balbach plant
in a table of other US electrolytic works (11 of them) on page 350 and
describes the application to nickel at Balbach in Volume 2, page 747.  He
says Elkington used Wilds magneto-electrical machines.  He mentions a number
of others who quickly picked up in Europe and elsewhere on the idea,
particularly crediting Branning and the firm of Siemens and Halske at Oker in
the Lower Harz where Branning was manager for their work with Siemens magneto
electric generating machines.  Again I saw no references to Mason from my
rather quick review.  Nichols Chemical used 3 GE dynamos.
    Piggot, Chemistry and Metallurgy of Copper (1858) is too early, and
Greenwood, Metallurgy (1874) for wet processing covers mainly chloride based
approaches (volume 2, page 62ff).  Howe, Copper Smelting (1885) covers only
pyromet processes (e.g., Welsh smelting/refining).
    These pretty well exhaust my library of early works.  Percy might have
something, but I don't have those volumes.  Some of the early "dictionaries"
of technology might also have something, but the Ure I've used in the past to
find copper material is too early (1839).
    I hesitate to say more since others probably already dug most or all of
these out.  Hope the above was of some help. If a paper was being written on
these plants, I'd appreciate hearing when and where it was published.

Larry M. Southwick (Cincinnati, Ohio)