Alkaline leach - filtration pilot plant testing of Monticello Blend of high lime ores

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U.S. ATOMIC ENERGY COMMISSION

RAW MATERIALS DEVELOPMENT LABORATORY

WINCHESTER, MASSACHUSETTS

. OPERATED BY

TOPICAL REPORT WIN - 106

,

ALKALINE LEACH - FILTRATION PILOT PLANT

]

TESTING OF

:!_ _ _ _ _

MONTICELLO BLEND OF HIGH LIME ORES

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·AEC·.·

RESEARCH ...

·lNtLOEVELOP.MENT···REPORT .

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WIN-106

Metal~urgy - Raw M,aterials

(M-3679 - 20th Edition Rev. 1)

1

-TOPICAL .REPORT lflN - 106

ALKALINE LEACH - FILTRATION l>ILOT 'PLANT

TESTING OF

MONTICELLO BLEND

OF

HIGH LIMa

.ORES

By

Howard

E.·

Dixon and Guy Winslow March 14, 1958 Approved

by~.£

..

w.

D. Charles SuperintendeJJ.'t

CJY~w~

Guy Winslow

U.

s.

Atomic Energy Co~ission

Contra.ct No. AT(49-6)-924

National Lead Company, Inc.

Raw Materials Development Laboratory Winchester, Massachusetts

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REPORT DISTRIBUTION

External Distribution

Allied Chemical and Dye Corporation Argonne National Laboratory

Atomic Energy Commission, Washington Battelle Memorial Institute

Chicago Operations Office Chicago Patent Group

Division of International Affairs (Bishop) Division of International Affairs (Pennington) Division of International Affairs (Woodruff) Division of Raw Materials

Fluor Corporation

General Electric Company, Richland Grand Junction Operations Office Hanford Operations Office

Iowa State College

Los Alamos Scientific Laboratory Mallinckrodt Chemical Works National Lead Company of Ohio

National Lead Company, Inc, (Monticello) New Brunswick Laboratory

New York Operations Office Patent Branch, Washington

Technical Information Service, Oak Ridge Union Carbide Nuclear Company (ORGDP) Union Carbide Nuclear Company (ORNL) U, S, Bureau of Mines, Salt Lake City

WIN-106

Metallurgy - Raw Materials (M-3679 - 20th Edition Rev, Number of Copies 1 2 2 1 1 1 1 1 1 12 1 2 4 1 1 1 3 1 1 1 1 1

University of California 'Radiation Laborator , Berkeley University of Nevada, Mackay School of Mines

40 2 5 1 1 1

List Pl'r letter Division of Raw Materials 8/lr/57 and additional memo 8/21/57

Internal Distribution G. W, Wunder R. G. Beverly Library 32 l 10 4

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ABSTRACT

WIN-106

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-During the period of January 2 to January 23, 1958, a blend of LaSal, Standard, and Jen ores from the Monticello stockpiles was treated in the Alkaline Leach,- Filtration Pilot Plant at Grand

Junction, Colorado. This report contains detailed information on

grinding, leaching, filtration, and precipitation in connection w.ith the processing of this ore. Autoclave leaching and

contin-uous NaOH precipitation were employed, The results show the ore

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ABSTRACT INTRODUCTION SUMMARY CHEMICAL COMPOSITION FLOWSHEET DESCRIPTION A. Grinding B. Thickening

c.

Leaching D. Filtration ·E. Clarification TABLE OF CONTENTS WIN-106 3 -2 4 5 6 7 7 7 9 10

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F. Continuous Yellow Cake Precipitation and Filtra.tion 10

G. Bicarbonation 10 TEST WORK A. Grinding 11 B. Thickening 11 C. Autoclave Leaching 13 D. Filtration 13

·E. Continuous Yellow Cake Precipitation and Filtration 17 ·

F. Reagent Consumption 17

METALLURGICAL BALANCE 21

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INTRODUCTION

WIN~l06

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-At the request of the Raw Materials Division of the U. S. -Atomic Energy Commission, a blend of La Sal, Standard, and Cord (Jen) ores from the Monticello stockpiles was treated in the Alkaline Leach

-Filtration Pilot Plant at Grand Junction, Colorado, The test

period was from January 2,to January 23, 1958.

The test was conducted primarily to obtain filtration and thick-ening data on this blend,

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SUMMARY

WIN-106

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-The results show the Monticello Blend of High Lime ore to be amenable to autoclave leaching in the Alkaline Leach - Filtration process.

A grind of 1.6 per cent plus 65 mesh and 62.8 per cent minus 200

mesh was sufficient for good leaching and filtration. In

thick-ening, 0.05 lb of flocculent per ton of ore was used as a settling aid.

The ore fed to the process during the run averaged 0.348% u3o8 • A leach residue of 0.015% u3o8 was obtained when leaching at

49 per cent solids. in an alkaline solution containing 50.4 g N'a2co3 .and 9.3 g NaHC03 per liter for 6.9 hours in a horizontal autoclave at 250•F. This leach was obtained using 50 psig pressure and 1055

scf of air per ton added for oxidation. ·

This ore exhibited fairly good filtration characteristics using 0.49 lb flocculent/ton. An .average filtration rate of 763 lb/sq ft/24 hr was obtained with a feed pulp containing 49 per cent solids. Soluble loss was 0.43 per cent· of the uranium contained in the mill feed.

Continuous precipitation of the yellow cake from the pregnant liquor was accomplished by heating the liquors to about l40"F and adding NaOH to an average exces.s of 5.8 g/1. The final product assayed 73.7% U308,

Reagent use was 4.6 lb Na2co3 , 0.25 lb .N'aHC03 and 31.3 lb NaoH per ton. In equivalent NaOH, the total consumption was 34.8 lb/ton. I\icarbonation of batten s,olutions requited 0, 50 gallon of No. 2 fuel oil/ton.

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CHEMICAL COMPOSITION

WIN-106 6

-A composite sample of the mill feed was chemically and

spectro-graphically analyzed ·at the Grand Junction Pilot Plant and ·

Winchester Laboratories, A .chemical analysis .of this sample of

Monticello High Lime Blend is presented in Table I. A

spectro-g.raphic analysis is shown in APpendix Table 1.

Component CaO MgO Mo Fe Cu C0 2

so

₄ (Soluble) S04 (Total)

s

Total carbon Table I Chemical Analysis Monticello High Lime Blend

Weight, % 0.35 56.7 14.1 1.40 0.06 0.08 0,007 1.55 0,02 10.6 0.16 0.90 0.17 2,99

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FLOWSHEET DESCRIPTION

WIN-106 7

-A detailed description of the flowsheet and process equipment has

been reported previously •

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However, the Fluosolids Reactor,

Peabody scrubber, and packed-tower bicarbonating units of the original flowsheet were not used for the processing of Monticello High Lime Blend as no roasting of the ore was required, A sub-merged .oil burner was .used for solution bicarbonation. The flowsheet that was used is shown in Figure 1 and is briefly des-cribed below.

A. Grinding

The ore as received from the Feed Preparation Plant has been crushed to minus 3/16-in. and is fed to a 3 x 5-ft ball mill operating in a closed circuit with a 18-in. x 13-ft Dorr rake classifier. Mill solution is added from a constant head tank to the ball mill and classifier to maintain the pulp at the desired densities for grinding,

B. Thickening

The classifier overflow is pumped to a 12 x 8-ft thickener to thicken the pulp and to maintain a constant pulp density to the leach circuit. Provisions are available for adding flocculents to the thickener feed pulp as an aid for settling and thickening the pulp.

C, ' Leaching

The underflow from the ball mill thickener is pumped to a Pachuca tank which serves as a surge vessel and is then sent through a

double pipe steam heat exchanger. Steam flows through an internal

1~-in. pipe and the pulp flows through the external. 3-in. pipe. Six passes approximately 20-ft long are used and the preheated

pulp is discharged into a horizontal autoclave for leaching, The

pulp in the autoclave is maintained at the desired leaching temp-erature by automatically controlled electrical strip heaters fastened to the bottom of the autoclave between the shell and the insulation.

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Topical Report WIN-19, Description of Alkaline Leach Pilot

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,~ GRINDING

*

No2 CO 3 ---, PRECIPITATION

a

C0₂BICARBONATION CAKE YELLOW CAKE

n

Figure 1 LEACHING SURGE TANK FILTRATION AUTOCLAVE

*

When Required

ALKALINE LEACH-FILTRATION WITH CONTINUOUS YELLOW CAKE PRECIPITATION

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''r

001-'

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WIN-106

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The horizontal autoclave is 4%-ft in diameter, 12-ft long, with 1%-ft dished heads, and is divided into three sections by over-lapping baffle plates. Each section is agitated with a 5-hp turbine-type agitator equipped with a 5-bladed 16-in. turbine, Operating capacity of the vessel is 1200 gallons. Air is added through a %-in. line discharging beneath each agitator. The quantity of air input is regulated by an automatic control valve. A spring-loaded reducing valve c'optrols the pressure in the

auto-clave, Pulp is discharged by the internal pressure through an

intermitteptly operated plug valve. The discharge valve is operated automatically by a pulp level control and is open approximately one minute at 20-minute intervals when the feed rate is 12 tons of ore per day at 50 per cent solids. Temp-erature and pressure losses in the discharge line between the autoclave and the top of a Pachuca, which is used as a surge vessel, dissipate sufficient heat and pressure that very little

flashing of steam occurs at the discharge.

D. Filtration

The leached pulp is discharged from the autoclave to the first of three 8-ft diameter x 4-ft cloth-covered vacuum drum filters operating in series. ·Each filter is operated approximately on a 30 - 55 - 15 cycle; vis., for each revolution of the drum, 30 per cent of the time of revolution is used for loading .or pick up, 55 per cent for drying and washing, and 15 per cent for the removal of the filter cake •. The vacuum measures 23-in.

of Hg at the filter heads. Pr.ovisions are made to add filtering

aids to the pulp feed for each filter.

Pregnant liquor containing the solubilized uranium: is drawn through the filter cloth of the first filter and pumped to the

unclarified storage tank, Filtrate of low uranium content from

the third filter is sprayed on the cake as the filter drum

revolves, displacing the pregnant liquor. The filter cake is

then removed and discharged into a repulper to which additional

filtrate from the third filter is added, This slurry is fed to

the second filter and the filtration process repeated. The

filtrate from the second filter is routed to the grinding c ir~

cuit to replace the solution removed with the solids in the

thickener underflow. The displacement wash used on the second

filter is bicarbonated barren liquor obtained from the precip-itation section and the cake is repulped also with this liquor and fed to the third filter. Water is used as the displacement

wash on the third filter. The filter cake is sampled, repulped,

with water, and pumped to. tails. Pr.ovisions are made to heat the pulp in each filter tub with a steam coil and to heat the wash for each filter with a double pipe heat exchanger,

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E. Clarification

The unclarified pregnant liquor is pumped from a storage tank through a plate and frame filter press into another storage tank. The clarification filter is cleaned at intervals and the solids discharged to tails.

F. Continuous Yellow Cake Precipitation and Filtration

The clarified leach liquor is pumped to the first of three 3,25 x

4-ft precipitation tanks arranged in series. ~ach tank is equipped

with a slow sweep agitator and steam coils. Caustic solution is

added to the pregnant liquor stream flowing to the first tank. The

.overflow from the third tank flows by gravity to a 5 x 5-ft thickener,

The thickener underflow is pumped to a 1.5 x l.O~ft vacuum drum filter.

Since the filter area is excessive, part of the filter cloth is blinded with a neoprene adhesive, thereby reducing the effective

area to 1.57 sq ft. The filtrate is returned to the thickener and

the thickener overflow flows by gravity to a 6 x 6-ft storage tank, The solution from this tank is pumped through a plate and frame filter press to remove any residual uranium precipitate. The press

filtrate is pumped to

co

₂ regeneration.

G. Bicarbonation

The barren liquor is bicarbonated before it is used for washing

and repulping the second filter cake, This is accomplished by

pumping the solution into the C0₂ regeneration tank and adding

co

₂ by means of a submerged oil 6urner burning No. 2 fuel oil,

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TEST WORK- MONTICELLqHIGH LIME BLEND

WIN~l06

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-Test work was initiated in the Alkaline Leach - Filtration circuit on January 2, 1958, using a mixture of Monticello stockpile ores. Th.e ore mixture contained 60% ;LaSal, 20% Cord (Jen), and 20%

Standard ores. The primary purpose of this test was to determine

settling and filtering characteristics of this blend of ores, Truck weights show that a total of 236.4 dry tons of the ore

mixture was treated. The ore had an averaged assay of 0.348%

u

₃

o

_{8 •}

The flowsheet shown in Figure 1 was used throughout the test. All leach tests were continuous.

A, Grinding ·

Screen analysis and U308 distribution of t4e ball mill feed are

presented in Appendix Table 2. The crushed ore (minus 3/16-in,)

was ground in mill solution with an average ball. mill pulp discharge of 62.8 per cent solids and an average classifier overflow density of 22.1 per .cent solids. The specific gravities of the mill solution

and ore were determined .to be (.08 and 2.65, respectively. As shown

in Table II, a grind of 1.6 per cent plus 65 mesh and 62.8 per cent

minus 200 mesh was obtained. The ore feed rate was 12,2 dry tons

per day. The ball charge in the grinding mill was 738 lb and the

ball consumption was about 1.0 lb/ton of ore. Daily grinding data are presented in Appendix Table 3.

B. Thickening

An average of 0.05 lb flocculent/ton of. ore was added to the thick-ener feed pulp as a settling aid for the ground ore in the thickthick-ener. The thickener underflow averaged 49 per cent solids. With a feed rate of 12.2 tons per day, the unit settling area in the thickener

was 9.27 sq ft/ton/day. This unit ar~a was more than sufficient

for settling the ore under the prescribed conditions. Laboratory

settling tests were run on both raw and leached pulps. Results are

presented in Table III. Settling tests on individual ores are

pre-sented in Appendix Table 10 Favorable settling 7ates were obtained

using 0.05 lb Separan 2610

.!/

or 0,05 lb S-3171

.!.

per t.on of ore.

The tests show that the raw .ore would require less settling area than the leached ore. Settling tests were run without pickets which

w.ould serve to explain the rather low terminal densities •

.!,/ The use of Separan 2610 and S-3171 does not constitute an endorse-ment of these products nor does it imply these are the only pro-ducts applicable.

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_{Table II}

Grinding Data

Alkaline Leach - Filtration Pilot Plant Monticello High Lime Blend

Ball charge, lb

Ore feed rate, tons/day

Ball mill discharge, % solids

Classifier overflow, % solids

Grind,

+

65 mesh, %

+

100 mesh, %

+

200 mesh, % - 200 mesh, % Table III WIN-106 12 -738 12.2 62.8 22.1 1.6 12.3 23.3 62.8

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Laboratory Settling Tests in Alkaline Carbonate Liquor

Monticello High Lime Blend

Terminal Density

Raw Ore, feed to BM thickener F D

-

R A % Solids

0.07 lb 2610/to.n 5,0 1.43 1.'19 5.1 43.1

Raw ore, 0.1, lb 2610/to.n 3.9 1.25 0.85 4.1 46.3

Raw ore, 0.05 lb 2610/ton 4.0 1.26 0.47 7.7 46.1

Raw ore, 0.1 lb s-3171/ton 3.9 1.22 1.38 2.6 46.9

Raw ore,0.05 lb S-3171/ton 3.9 1.24

o.

72 4.9 46.7

Leached ore, 0.05 lb 2610/ton 3.4 1.02 0.38 8.3 51.5

Leached ore, 0.1 lb 2610/ton 3.5 1.05 0.45 7.2 49.1

Leached ore~ 0.05 lb S~3171/ton 3.4 1.06 0,50 6.2 50.9

Leached ore, 0.10 lb s-3171/ton 3.4 1.03 0.80 3.9 51.2

Calculations are based on the Coe-Clevenger formula: A= 1.333 (F-Ii)

where A= Thickener area - square feet/ton/day

F

=

Initial dilution - tons solution/ton ore

D = Final dilution - tons solution/ton ore

R = Settling rate - feet/ho.ur

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C. Autoclave Leaching

WIN-106

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-With an average belt feed assay of 0.348%

u

₃

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_{8 and a thickener} underflow residue of 0.254% U308 for the entire run, extraction in the grinding and thickening circuits amounted to 27.0 per cent of the uranium in the Jllill feed. _{The Na2}

co

₃concentration of the grinding solution ave.raged 50.4 g/1 and the NaHC03 concentration averaged 9. 3 g/1. Barren solutions wer.e bicarbortated to 7 - 10 g NaHC03/1.

A su)lllllary of the leaching data is p!resented in Table IV. The pulp was held at 250°F and 50 psig. Air

was

added to the auto-clave at an average ra.te of 1055 &cf/ton {0. 733 scfm/tpd). T\le shaft speed was 190 rpm (796 ft/min agitator peripheral speed) and the power consu:m.ption amounted to 12.1 hp-hr/ton. Steam consu:m.ption at 100 psig amounted to 455 lb/ton. The above con-ditions res1,llted in a 92.5 per cent leach extraction (residue 0.026% U30s) after 2,3 hours and a 95.7 per cent leach extraction

(residue 0.015% U30s) after 6;9 hou.rs. Daily leach data are presented in Appendix Table 4.

D. Filtration

The vacuum drum fitters were of such size that they would filter more leach residue than was produced in the leaching operations; therefore, the leach pul.p was stored for short periods in Fachuca tanks and the filtration circuit was operated intermittently. While

a.

ba.tch of pulp was being filtered freshly leached pulp was entering one of the storage I'achuca tanks. Therefore, filter ra.tes were calculated from pulp flowrate and density data.. The filters were operated on a 2-minute cycle during the test. The l/ cl.oth used to cover the drums w/8,S National. Filter Media, NS1201 -which is .. a· nylon twill filter cloth woven with a nap surface. The cloth was installed with the nap surface exposed.

Filtration data are presented in Table

v._

The No. 1 filter feed density averaged 1.52 (49 per cent solids) and the pulp te:m.perature in the filter tub averaged 137°F. The filtration rate was. 763 lb/sq ft/24 hr with a soluble loss of 0.43 per cent of the uranium contained in the mill feed. The reagent loss, expressed as mole equivalents of NaDH and based on Na.2C03 and NaHC03 assays of the solution in the No. 3 filter cake, amounted to 7. 9 lb NaOH/ton. The moisture in the filter cakes. averaged 23 per cent. Total

flocculent addition .amounted to 0.49 lb Separan 2610 per ton of ore. Daily filtration data are presented in Appendix Tables 5, 6, and 7.

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WIN-106

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The solution flowsheet for the run is shown in Figure 2o Water

added to the Noo 3 filter a~ounted to Oo24 ton per ton or oreo

Evapo:ration in the leach circuit a~ounted to Oo05 ton of solution

per ton of oreo Water to the ball ~ill (Oo02 ton) was introduced

as ~oisture in the oreo

Table IV

Auto.clave Leaching· Data

Alkaline Leach - Filtration Pilot Plant

Monticello High L i - Blend

Ore feed rate :

Te~perature:

12 o2 tpd

zso•F

Average grind: lo6%

+

65 and 62o8% -200 ~esh

Ore, %

u

₃

o

₈

Grinding solution, g/1

Pressure, psig

Shaft speed, rp~

Power cons=ption, hp-hr/ton Air, scf/ton

Off gas, %

o

₂

Oz consu-d, scf/ton

Ste= cons~d, lb/ton

Autoclave Discharge, g/1

Leach Residue, % U30s

2o3 hr o026 4.6 hr o018 6o9 hr o015 U308 2o3 4o6 6o9 Oo348 50o4 9o3 50 190 12ol 1055 14o5 68,6 455 39 0 9 15o 7 Extraction, hr 92o5 hr 94o8 hr 95.7 %

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Table V

Filtration Data

Filter cycle: 2 minutes

No. 1 Filter Feed

density, g/ml

temp, "'F

No. 1 .Filter Tub, temp, °F

Tons filtered

Filter operating hours Tons/hr

Lb/sq ft/24 hr

Ore feed assay, % U308

Filter Cakes, % Hz.O

No. 1 filter

_No. 2 filter No. 3 filter

No. 3 Filter Cake Sol'n, g/1

Soluble loss, %

Reagent loss as lb NaOH/ton

£/

Flocculent Addition, lb Separan/ton

No. 1 filter No. 2 filter No. 3 filter Total WIN-106 15 -1.52

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144 137 237 149.4 1.59 763 0.348 23.5 22.3 23.3 0.049 14.3 4.5 0.43 7.9 0.31 0.09 0.09 0.49

1/ ·corrected for 11% air by v:olume in pulp.

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Mill Solution

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.56 I • 2.97 2

:ss

.30 /

t\

.98 1.03 Moisture in blend .02 .

,,.

Grinding

.

Thickening 1.0 Leaching .95 No, 1 Filter .73 • 96 lr No. 2 Filter .22

L

I

• 80 1.02 No. 3 Filter WIN-106 16

-..

.05 (Evaporation) •

Water with flocculent .02 1.04

.I

Precipitation 1.04 ,24 Bicarbonation Wash water .24 • 23 to tails

Figures are ton solution per ton of ore Figure 2

Alkaline Leach - Flltration - Pilot Plant Solution Balance

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WIN-106 17

-'--- E. Continuous Yellow Cake Precipitation and Filtration

Precipitation data are presented in Table VI. Yellow cake was

prec!pitated from the alkaline leach liquors by adding NaOH to

an excess of 6 g/L The caustic, as a 25 per cent solution, was added to the pregnant liquor before entering the first of three precipitation tanks. The pregnant liquor grade averaged 3.69 g U308 , 46.6 g Na2C03, and 14.4 g Nalico3 per liter. The average temperature used in the precipitation circuit was 140°F. With an NaOH excess of 5.8 g/1, the barren averaged 0.087 g U308/L The average pregnant liquor flowrate .was 2.28 gpmwhich gave a calculated residence time of 4.3 hours in the circuit.

Yellow ca:ke filtration rates averaged 384 lb/sq ft/24 hr and the cake contained 37.7 per cent moisture. The .average cake

gr~tde _{was 73.7% U3o8 • :Oaily precipitation and filtration data}

.are presented in Appendix Table 8. Analyses of a composite of yellow cake produced is presented in Table VII, Only one drum filter was available to the yellow cake recovery circuit. If

it had been possible

to

repulp the cake and include a second

stage of filtration it is probable .the c.oncentrate would meet both uranium and carbonate specifications.

F• Reagent Consumption

Invent:ory and reagent consumption data for autoclave leaching of Monticello High Lime Blend ore are shown in Table VIIL At the

be~inning of the run there was 109.6 tons of solution in inventory. A':totaL.bf 90.•0-.solution·:toris· .. had an .. .average·:calcula!;oad concentration of 50.1 g .NazC03 ahd 10 •. 5 .g NaHC03 per l;Lter. The .remainder .. (l9.6 tons) averaged 50.1 g Na2co3 and 8.7 g NaOH per liter. Other than a small amount of NaHC03 added intially, only Na.OH addition and bicarbonation were necessary to maintain constant reagent strength.

The barren solution was bicarbonated to 7 " 10 g NaHC03/l. The

net reagent use based on inventory and reagent additions was 4,6 lb Na2C03, 0,25 lb NaHC03, and 3L3 lb N!lOH per ton. This reagent use was equivalent to 46.1 lb Na2co3 or 34.8 lb NaOH per ton. In

addition, bicarbonation of barren solution required O.So gallon

of No. 2 fuel air/ton, Inventory data are presented in Appendix

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Table VI

Continuous Yellow Cake Precipitation and Filtration Data Alkaline Leach - Filtration Pilot Plant

Monticello High Lime Blend

Pregnant liquor flowrate: Precipitation time: Pregnant Liquor, g/1 Temperature, "F NaOH flowrate,

!/

gpm Barren Liquor, g/1 Filtration rate, lb/sq ft/24 hr Tub temperature, °F Filte~ cake, % ~0

!/

Added as 25% solution 2.28 gpm 4.3 hr 3.69 46.6 14.4 140 0,12 0.087 5.8 384 154 37.7

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Table VII

Analyses of'concentrate

Alkaline Leach ~ :Filtration Pilot Plant Monticello High Lime Blend

Constituent Weight, % WIN-106 ~ 19 -U308 74.70

1.1

V21l5 3.30

ll

P04 0.39 Mo 0.017 B .c:O .0025 Halogens 0.06 F .c:O.Ol Fe 0.072 Cu 0.037 As 0.008

ca

0.13 so4 L36 Insoluble 0.42 co3 5.5611

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Table VIII

WIN-106 20

-Inventory and Reagent Consumption Data

Alkaline Leach - Filtration ~ilot Plant

Monticello High Lime Blend Autoclave Leaching 236.4 tons .of ore

Sol'n Tons

Calculated Assay, g/1

Na2CO~ _NaHC03 Na0H

Actual gounds. in Inventory

Na2C03 .:. NallC0_{3 : ...}NaOH

Inventory 1/2 90.0

.!2.:..2.

Total 109.6 Inventory 1/23 87.0

1.!.:.2

Total 98.5

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Inventory change -11.1 50.1 50.1 50.2 50;2 10.5 10.7 8.7 4.1 9018.0 1963.9 10981.9 8734.8 1154.6 9889.4 -1092.5

Reagent Use Na₂co~

From inventory, lb 1092.5

From addition, lb

:Total, lb 1092.5

1b/ton 4.6

Equivalent NaOH, lb/ton 3.5

Net Reagent Use

Equivalent NaOH (total), lb/ton

No. 2 fuel oil for bicarbonation, gallon/ton

.

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1890.0 341.0 1890.0 341.0 1861.8

.2id

1861.8 94.3 -28.2 -246.7 NaHC03

_N!llli

28.2 246.7 30.0 7159.2 58.2 7405.9 0.25 31.3 0.01 31.3 34.8 0.50

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METALLURGICAL BALANCE

A metallurgical balance for the Alkaline Leach - Filtration Pilbt Plant when the Monticello Blend was treated in presented

·in Table IX. The uranium content and quantity of ore processed

are based on truck weights and samples taken in the Feed

Prepar-ation Plant, The calculated

u

₃

o

_{8 recovery amounted to 96.5}

per cent, Actual recovery based on barrel weights and assays was 97.0 per cent resulting in an unaccountable gain of

0,50 per cent.

Table IX

Metallurgical Balance

Total

Dry

_uta

Sol'n

_{ur~8 ut~8}

Tons Tons % of Total

-Ore processed 236.4 0.348 1645.3 Inventory 1/2 none 109.6 284.6 284,6 Inventory 1/23 none 98.5 255.9 255.9 Inventory change -11.1 -28.7 -28.7 Uranium processed 16 74.0 100.0 Soluble loss 7.2 0.4 Residue 236.4 0.011 52.0 3.1 Calculated recovery 1614.8 96.5 Yellow cake, 2124.5 lb 73.73 1566.4 93.6

Yellow cake, (cleanup)

79.61 lb 71.32 56.8 3.4

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APPENDIX WIN-106 - 22 ~

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Table 1

Spectrographic Analysis Monticello High Lime Blend

Element Si Al Ca Fe Ba Mg Na

c

Sr u Mn Ti

v

Zr Li Cr Cu Mo Ni WIN-106 23 -Assal: Ran!le, % >10 1 - 10 1 - 10 1 - 10 Ool - 1 Ool - 1 Ool - 1 Ool - 1 Oo 1 - 1 OoOl - Ool OoOl - Ool OoOl - 0.1 OoOl - Ool ( OoOl OoOOl - OoOl OoOOl - OoOl OoOOl ~ OoOl <ooOOl

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Table 2

Screen Analysis - Ball Mill Feed Composite Monticello Hign Lime Blend

Head Assay: _{0.348% u3}

o

₈

Screen

S,ize % Retained Assay U30o Distribution, %

Mesh Weight Cumulative _{% U308} Weight Cumulative

+.525 in. 2.6 2.6 .154 1.3 1.3 +.371 in .. 11.2 13.8 .201 7ol 8.4 + 3 8.6 22.4 ,303 8.2 16.6

+

4 8.3 30.7 .403 10.6 27.2 + 6 7.9 38.6 .432 10.7 37.9 + 8 5.8 44.4 .473 8,8 46.7 + 10 6.3 50.7 .467 9.2 55.9 + 14 5.6 56.3 .365 6.5 62.4

c

+ 20 5.7 62.0 .323 5.8 68.2 + 28 5.2 67.2 .266 4.4 72.6 + 35 6.0 73.2 .282 5.4 78,0 + 48 5.6 78.8 .261 4.7 82.7 + 65 4.9 83.7 .266 4.2 86.9 +100 5.2 88.9 .250 4.1 91.0 +150 3.0 91.9 .240 2.3 93.3 +200 2.1 94.0 .249 1.6 94.9 +270 1.4 95.4 ,257 1.1 96 .o +325 2.0 97.4 .245 1.5 97.5 -325 2.6 2.6 .300 2.5 2.5 100,0 100.0 Calculated head: 0.316% u₃o₈

(

(28)

.~

n

' l

Table 3

Grinding and Thickening Data Monticello High Lime Blend

Grinding Circuit Thickener Circuit

Ball Mill Densit:t: 1/ Grind, Classifier O'flow Sepa.ran

Date Operating Dry Ball Mill Class + 65 +100 +200 +325 -325 2610 'rhick. U'flmi

1958 Hour 1'£!1§. Discharge 01flow _~Mesh Mesh Mesh ~ 1b/ton Density _!£!!!

1/2 13.83 6.75 1. 70 1.22 1.4 9.0 23.9 15.5 50.1 .08 1.52 2.56 1/3 24.00 12.15 1.71 1.23 1.3 9.9 20.3 11.6 56.9 .08 1.52 2.98 1/4 24.00 12.56 1.72 1.23 0.9 9.3 23.1 13.6 53.0 .08 1.52 2.91 1/5 24.00 12.23 1. 73 1.23 1.1 10.8 22.8 12.7 52.7 .07 1.51 2.86 1/6 24.00 12.16 1.73 1.23 1.2 11.9 22.8 12.5 51.6 .08 1.53 2.77 1/7 24.00 12.19 1.72 1.23 1.0 11.6 25.0 14.4 48.0 .07 1.52 2.96 l/8 24.00 12.03 1. 72 1,23 1.7 14.2 23.2 12.6 48.3 .07 1.52 3.05 1/9 24.00 12.28 1.72 1.24 1.8 14.1 23.9 12.9 47.3 .08 1.51 2 .• 88 1/10 24.00 12.21 1.71 1.24 1.5 11.9 23.4 12.9 50.3 .08 1.52 2.92 1/11 24.00 12.14 1.71 1.24 1.9 13.4 23.9 13.2 47.6 .07 1.51 3.00 l/12 24.00 12.10 1.71 1.24 2.7 13.2 21.0 11.2 51.9 .08 1.52 2.97 1/13 24.00 12.07 1.71 1.24 1.6 12.3 24.0 13.0 49.1 .08 1.50 3.15 1/14 24.00 12.22 1.71 1.24 2.0 14.4 25.1 12.3 46.2 .08 1.52 2.78 1/15 24.00 12.03 1,72 1.24 1.7 13.3 21.9 12.3 50.8 .08 1.52 2.81 1/16 24.00 12.15 1.73 1.24 1..7. 12.4 22.6 12.6 50.7 .07 1.53 2.77 1/17 24.00 12.21 1.73 1.25 1.3 11.0 22.0 12.7 53.0 .08 1.52 2.96 1/18 24.00 12.48 1.71 1.24 1.4 13.0 24.6 13.5 47.5 .07 1.52 2.94 1/19 24.00 12.00 1.71 1.24 1.3. 12.7 23.9 13.3 48.8 .08 1.53 2.91

....

,..,

1/20 24.00 12.29 1.72 1.24 1.3 13.7 25.3 11.8 47.9 .07 1.52 2.81 N2:

"'

'

l/21 22.67 11.33 1.71 1.24 2.6 14.2 23.6 13.2 46.4 .08 1.51 2.79

....

' .0

"'

Avg 1.72 1.24 1.6 12.3 23.3 12,9 49.9 .08 1.52 2.89 Total 468.50 237.58

(29)

~ Tablr-''t_ · j

Daili Leachin~ Data

·Monticello High Lime Blend Pressure: 50 psig

Temperature: 25o•F Pulp: 49'7. solids

Aeration air: 1055 scf/ton

Mill Thick. U'flow 2,3 Hr. 4.6 Hr. 6.9 Hour

Date· Feed Grindin~ Sol'n, a/1 Residue Residue Residue Residue Solution, &11

1958 l!.U.J2a §Qg. . Na,.COl NaHC03

%

U3Qa % U308 % UJ,Qa %U~ Na~3 NaHro;r

1/2 .349 0.99 49.98 8,11 ,240 ,027 .019 ,018 39.27 13.10 1/3 • 271 1.42 49.29 9.45 ,236 . .025 .017 .014 39.26 12.96 1/4 .479 i.29 49.13 9.58 ,241 .024 .018 .015 39.24 13.94 1/5 .352 1.14 51.99 9.16 ,250 .026 .017 .013 40.21 15.26 1/6 ,352 1.22 53.58 7.90 .239 .028 .018 .016 39.61 17.58 1/7 .361 1.26 53.00 7.56 .234 ,026 .017 .015 42,79 15.49 1/8 ,289 1.21 54.06 7.98 ,228 ,022 ,016 .013 42.93 16.10 1/9 .343 1.10 51.94 9.66 ,232 .023 .016 ,013 41.69 14,98 1/10 .377 1.14 50.35 11.34 .246 .021 .016 .013 40,28 15.54 1/11 .366 1.12 50.35 8.82 ,258 ,023 ,016 ,013 39.33 17.57 1/12 .301 1.10 50.00 10.20 ,284 ,029 .018 ,017 39.17 17.40 1/13 .416 1.11 49.50 9.74 ,252 ,025 .018 .016 - 39.52 17.17 1/14 .264 0.97 50.40 8,74 ,285 .029 ,020 ,016 39,06 16.58 1/15 .439 1.00 50.14 8,53 ,267 ,024 ,019 ,016 40.16 14.95 1/16 ,260 1.11 49.45 8,06 ,229 ,029 ,018 ,014 40.30 15.78 1/17 .298 1.07 48.92 9.03 ,261 ,025 ,017 ,014 39.45 16.54 l/18 .391 1.08 50.62 8.48 ,265 .030 ,020 .017 40.42 14.98 _>':: 1/19 ,327 1.09 49.44 9,61 ,260 .oz8 ,017 .016 38.89 15.88 i H z 1/20 .360 1.04 48.28 11.26 ,299 ,025 .019 -,017 39.62 14.75

"'

_"'

_{,_.}

_'

1/21 .355 1.03 47.75 11.72 .277 ,028 ,018 .016 36.87 17.24 0

'

""

Avg .348 1.13 50.4 9.3 .254 ,026 .018 ,015 39.90 15,69

(30)

r-

~~-.::!.. _\ I

,---\

Daily Filtration Data Monticello High Lime Blend

No. 1 Filter

cake

_1/

Filter Feed ReS:idue Filtrate Flocc

D.ate Fil'n U308 Na2co3 NaHC03 ])enS: Temp Tot.al _H2o _{wash u3o8 Na2co3 NaHC03 Add'n} 1958 . No.

..$11;.

g/1 g/1

BEl!!._

g/111l. ".c % _u3o8

_...L

sa.

...&1..1

g /1 T{/1 .. 111l../min

~ 1/3 1 3.76 :38.2 13.4 10.8 1.37 46.2 .034 24.9 2.24 3.39 43.6 12,0 720 1/4 2 4,_34 43.3 13.3 10.5 1.39 50.7 ,052 23.7 1.85 3.94 44 •. 8 13.9 495 1/5 3 3.58 41.6 16.0 10.8 1.41 59.2 .064 22.6 2.00 2.88 44.7 16.5 400 1/6 4 4,47 43,5 16.4 14.0 1.36. 59.5 .073 22.9 2.05 4.54 45.6 15.5 475 1/7 5 4.52 44.5 15.1 11.5 1.35 62.8 .061 25.1 2,00 4.28 45.1. 16.8 43:5 1/8 6 4.06 41.3 1.2.6 10.4 1.33 61.2 .065 23.3 2.00 3.75 46.6 15.5 403 1/9 7 4.42 43.5 16.6 11.0 1.32 62.3 .06.2 22.5 2.05 4.07 47.5 16.9 440 1/10 8 4.44 40.8 16.3 12.0 1.37 67.0 .055 23,1 2.07 4.25 45.6 16.8 497 1/ll 9 4.81 43.1 17.6 10~0 t•;36 63~5 ·;:Q16 22.6 1.98 4~04 45.6 1L2 345 1/12 10 4.29 42.5 16.7 11.8 1.37 69.8. .077 23.9 2.00 4,0.0 46.1 15.5 453 1/13 11 4.98 41.1 16.3

n.o

1.44 62.0 .058 22,9 2.00 4.61 53.1 15.5 542 1/14 12 3.89 41.1 15.5 12,3 1.36 69.7 .061 22.8 2.00 3.93 45.9 13.2 600 1/15 13 4.39 .43.2 14.9 9.5 1.36 59.5 .0.63 26.9 1.68 3.79 44.5 15.0 586 1/16 14 4.56 41.8 15.5 10 •. 8 1 .• 36 67.7 .038 22.9 2.07 4,21 44.5 15.2 573 1/17 15 4.8.5 42.1 15.8 10.3 1.36 61.7 ,0:32 24.0 1.80 4.27 43.0 15.9 673 1/18 16 4.88 42.9 14.9 11.7 1.39 67.3 .056 23.9 1.87 4.65 44.5 15.3 613 l/19 17 4.88 42.5 17.7 8.3 1.39 59.7 .057 22.4 1.43 4.17 42.7 16.8 540 1/20 18 4.62 43.5 15.3 :9.3 1.37 64.3 .070 23 .• 7 1.55 4.11 44.3 14.7 493 1/21 19 4.39 39.5 15.1 9.8 1.36 65.3 .059 22.2 1.60 4.28 42.4 15.5 488 _.~ Avg 42.1 15.4 10.8 . 1.:37 .059 23.5 1.91 514

_""'

z

9.6'!:h.52Y

.... 1-' . 0

'""

1/ 0,719 per cent solution

'if

corrected for 11 per cent jrlr by volume in pulp ~

(31)

c

(

Date Fil'n 1958 No. 1/3 1 1/4 2 1/5 3 1/6 4 1/7 5 1/8 6 1/9 7 1/10 8 1/11 9 1/12 10 1/13 11 1/14 12 1/15 13 1/16 14 1/17 15 1/18 16 1/19 17 1/20 18 1/21 19 Avg Table 6

No. 2 Filter

WIN-106 - 28 •

Cake

Residue Bicarbonated Barren Filtrate Feed Flocc

Total _HtO

% U30S Nalco3 NaHC03 Wash

u

₃

o~ Na

7

co3 NaHC03 Pulp Add'n /

g 1 g/1 gp.!!L.

....iJ.J:.

g 1 g/1 ~ ml/min

l

.016 22.2 58.7 10.0 1.6 .73 55.2 11.0 1.48 150 .016 22,2 59.4 10.5 1.5 .50 58.4 6.2 1.46 167 .024 23.9 64.1 7.1 1.7 .75 59.9 6,7 .1.51 150 .025 23.6 54.1 5.5 1.8 • 84 54.6 7.6 1.50 135 .017 21.9 53.0 8.0 1.4 • 75 5.1. 9 8.8 1.45 140 .015 21.4 54.1 8.8 1.4 .70 51.4 10.1 1.49 160 .015 22;8 54.1 7;1 2.0 ,61 53.0 4.2 1.47 135 .016 23.5 53.3 8.7 2.1 .53 52.5 10.1 1.47 128 .014 22,5 54.0 8.2 1.7 .52 51.9 8.8 1.46 135 .018 21.7 55.2 5.9 1.5 .61 52.6 6.4 1.46 150 .016 22.1 55.1 6.0 1.4 .62 53.8 5.8 1.48 160 .014 22.8 55.2 5.8 1.8 .70 48.3 10.4 1.48 160 .017 23.3 56.2 7.1 1.7 .60 51.6 9.0 1.46 154 .017 22.0 57.2 7.9 1.3 .60 54.2 8.6 1.47 150 .017 22.4 54.3 9.9 1.4 .74 52 .• 8 9.1 1.49 150 .020 21.8 56.2 8.0 1.4 .73 51.5 9.7 1.47 150 .019 21.0 54.4 9.2 1.3 .46 50.4 10.3 1.49 150 .017 20.8 58.3 9.8 1.2. .59 50.9 8. 7 1.45 150 .014 22.5 59.5 8.0 1.0 .56 49.9 9.7 1.45 145 .017 22.3 1.5 1.47 148.

(32)

r-,

n

r1

'

Table 7

No. 3 Filter F i~l"'"te-r----oc:-a.,...ke----'=..::.

Feed Residue Flocc

Date Fil ~n Pulp "J:otal Insol ~0 Solution, g/1 Wash Filtrate, g/1 Add 'n

1958 ....lli'..:..._ Dens _{% U30"'- %}

u

₃

o

₁₁ _%_. _ ~ _Na2COJ NaHCOJ ~ ~ N"'>~Jl, N1iHCO, ml/min

!f

1/3 1 1.46 .014 -.012 24.1 .019 6.7 2.5 1.7 ,141 55.9 10.3 140 1/4 2 1.43 .012 .011 22.4 .030 9.5 4.5 1.5 .130 58,8 5.5 163 1/5 3 1.50 .064 .012 24.5 .030 27.8 7.4 1.6 ,219 60.9 7.1 140 1/6 4 1.50 .017 .013 22.4 .119 27.4 2.5 1.9 ,230 54,1 7.6 130 1/7 5 1.46 .011 .009 23.2 .076 16.4 4.8 1.8 ,192 50.4 8.8 125 1/8 6 1.48 .011 ,009 22.6 .039 11.8 2.0 1.4 .150 51.9 7.6 145 l/9 7 1.46 .011 .010 24.8 .027 7.5 3.5 1.5 .140 51.4 5.9 130 l/10 8 1.48 .011 .009 23.7 .047 14.5 5.2 1.2 .126 51.4 9.2 123 1/11 9 1.49 .012 .011 22.8 .039 12.9 4.8 1.8 .122 50.9 7.3 100 1/12 10 1.48 .014 .012 21.8 .071 23.2 7~9 1.5 .148 51.7 6.3 100 1/13 11 1.48 .013 .012 26.4 .017 13.2 4.0 1.8 .123 56.2 5.8 133 1/14 12 1.48 .011 .009 23.3 .038 13.5 2.8 1.7 .138 52.5 5.9 160 l/15 13 1.45 .011 .010 24.2 .004 7.9 4.6 1.5 .127 49.8 7.6 135 1/16 14 1.47 .011 .010 22.5 .060 17.8 4.8 1.5 .152 55.1 7.1 133 1/17 15 1.49 .012 .011 23.1 .077 18.5 6.9 1.4 .145 53.8 8.6 133 1/18 16 1.50 .013 .013 22.8 .049 13.2 4.7 L4 .168 53.7 7.7 130 l/19 17 1.50 .013 • .013. 22.7 .088 18.3 8.2 1.3 .112 47.7 10.1 133 1/20 18 1.45 .013 .011 22.9 .029 9.3 2.8 1.2 .132 51.4 8.4 138 ' ~ l/21 19 1.46 .011 .011 23.1 .048 15.8 4.5 1.0 .130 52.5 8.4 140

"''f

\0 I-' 0 Avg 1.48 .015 .011 23.3 ,048 1.5 133 '

(33)

~ , ( \ '· I

~ie 8

Daily Precipitation Data Monticello High Lime Blend

Clarified

Pregnant Liguor Precipitation

Date Ppt. Flow U308 Na2

co

_{3 NaHC03 Temp NaOH Res. Time} Time_,

1958 No. gpm g/1 g/1 g/1

_:r_

_~Hr Hr 1/5 1 2.00 3.67 44.2 12.9 140 .12 4. 7 2.8 1/7 2 2.00 3.09 48.3 13.7 140 .12 4.7 7.7 1/9 3 2.00 3.93 52.5 10.9 140 .12 4.7 8.5 1/10 4 1.80 3.94 46.6 15.1 140 .12 5.2 8.1 1/12 5 1. 75 3.82 46.1 16.4 140 .11 5.4 7.5 1/14 6 1.84 3.30 47.7 13.1 140 .11 5.1 8.0 1/16 7 2.10 3. 89 47.3 15.3 140 .11 4.5 8.3 1/18 8 2.47 3.58 46.6 14.4 140 .13 3.8 13.8 1/19 9 2. 71 3.55 45.6 14.9 140 .13 3.5 4. 7 1/20 10 2 •. 75 4.06 45.1 .15.4 140 .13 3.4 11.3 1/21 11 2.98 3.84 44.5 15.4 140 .14 3.1 5.5 1/23 12 3.00 3.61 45.2 14.8 140 .14 3.1 8.6 Avg 2.28 3.69 46.6 14.4 140 .12 4.3 7.9

.7'\

Filtration Barren Filtrate

lb/sq ft/

Ht

24 hr. --2- ~ !la7CO~ NaOH

570 32.0 .128 64.1 5.4 560 36.8 .096 66.3 5.2 345 37.7 .110 77.9 5.4 337 38.9 .079 86.4 6.9 398 37.4 .074 75.3 6.6 401 34.4 .071 67.6 7.0 288 32.4 .079 67.6 5.9 260 40.2 .073 66.1 6.1 349 39.8 .086 74.0 5.1 192 42,3 1077 70,1 5.7 555 41.8 .077 65.1 5.0 357 38.4 .095 63.3 5.2 384 37.7 .087 70.3 5.8

""

'!2!

W I Ot-' 0

(34)

oa-~.

n

Table 9

.Inventory Data ~ Alkaline Leach - Filtration Pilut Pla.nt

Monticello High Lime. Blend

Sol'n 1L2l58 .. Assa::z:, aZ1

sof

1

n

Description Tons. Na~.co~ NIUICO"'. ~ N&OH

_!!.3.Qg,

Tons Nli:;~C03

Thickener 28,2 44.0 8,3

-

0.990 28 •. 2 48.3

No. 2 l'achu.ca 19.6 42.1 15.4

-

0.203 none

No. 1 mill s.olution 11.1 52.0 9.2

-

1.02 12.3 49.3

No. 2 mill solution 7.7 57.2 8.8

-

0.272 11.4 50.9

No. 1 .barren storage 6.3 56.7

-

5.5 0.068 none

No. 2 barren storage 8,5 56.5

-

12.8 0.049 10.9 52.8

Unclarified preg none

-

12.3 47.1

Clarified preg none

-

~

.

-

4.9 45.8

U308 precip 6.7 43.5 13.0

-

3,73 7.1 45.3

C02 regeneration 16.7 59.9 8.8

-

0.0.85 1L4 56.2

Cont, precip tanks. 2.3 58.2

-

5.5 1.23 none

Cont. precip thickener. ;t;s 58.4

-

6.0 0.087 _~

To.tal 109.6 98.5 "l/23Lss .Aas4::z:l a,/1 NaHCO@ . NaOH 9.3 ~ 9.8

-8.3

-l.l.l

-12.8

-14.6

-15.2

--

4~1 ·~ u~o₈ 1.15 1.02 0,50 0.085 2,23 3.08 3,52 0.084

,;':l

w-~

_{,_..}

_{,_..} 0 I " '

(35)

(

Ore Standard Cord (Jen)

c

LaSal

(

Table 10

Laboratory Settling Tests on Monticello Ores

Flocculent, lb/t.on

r

_!

R 0.1 2610 3.2 0.59 2.0 .8 0.05 2610 3.2 0.61 14.1 0.1 3171 3.2 0.61 24.2 0.05 3171 3.2 0.63 13.5 0.1 2610 3.2 0.99 0,59 0.05 .2610 3.2 1.03 0.38 0.1 3171 3.2 0.86 0.80 0.05 3171 3.2 0.88 0.72 0.1 2610 3.2 0.77 0.69 0.05 2610 3.2 0.85 0.24 0.1 3171 3.2

o.

77 0.85 0.05 3171 3.2 0.81 0.31 WIN-106 32

-A

0.17 0.24 0.14 0.25 5.0 7.6 3.9 4.3 4 •. 2 13.0 3.8 10.3