第二章 重力选矿基本原理 2.1 概述 2.2 颗粒 (particle) 及颗粒群沉降...
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浮力 阻力 重力. 第二章 重力选矿基本原理 2.1 概述 2.2 颗粒 (Particle) 及颗粒群沉降 (settling) 理论 2.2.1 矿粒在介质 ( Medium) 中的自由沉降 １、矿粒在介质中所受的重力 矿粒在介质中所受的重力， 等于它在真空中所受的重力 与浮力之差．. 根据阿基米德原理 G 0 =Vδ g- Vρ g = (m/V)δ g – (m/V)ρ g = m ((δ- ρ ） /δ)g - PowerPoint PPT PresentationTRANSCRIPT
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2.1 2.2 (Particle)(settling)2.2.1 (Medium)
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G0 =V g- V g = (m/V) g (m/V) g = m ((- /)g G0 = m g0 Vm3 k/m3 kg/m3 g m/s2 m kg , m/s2
- g0 >
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1)
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2) a RR vdR:R= f(v, d , , )
- Re
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1 < Re500 , =10 , k=1/2
Re=2~300
- 3) 500
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ReRe (LRayleigh)Re
Re2-2-2
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2-2-1
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3 1) a
R
G0
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dv/dt =g0 a a
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dv/dtvdv/dt R=G0 =0 v0 R=G0
(2-2-12
dv0 d v0 v=v0 Re
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~ f(Re) , Re =vd/ 2-2-122-2-13v0 d
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d v0 d v0 (RLunnon) d ( v0)Re ,
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=f(Re) Re2 Re /Re Re
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1(Terminal Velocity)G0 = R
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Re 1 Re
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2v0 R=G
CGS
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3-v0 R=G
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CGS
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2-3
Re
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1 d dV k v0k
(2-2-23)
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dV =d
2-67 v0k =v0 (2-68) 2-2-2 2-2-3
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:
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4 dV1 1 dV2 2 2 > 1 v01 =v02 ,dV1 >dV2 e0 e0 = dV1/dV2 >1
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dV1/dV2 < e0 v02 > v01 , dV1/dV2 = e0 v02 = v01 , dV1/dV2 > e0 v02 < v01 , dV1/dV2 e0
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(1),
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(2)
(3)
(4)
m,n Re
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e0e0 () 1400kg/m32200kg/m3e0=158 , e0 = 2.75
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()uo mnv0Re
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1=2650kg/m32 =7500kg/m3 v0=l2cm/se0 =2.42=60cm/se0=342e0 ()
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11 2
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34 2
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= Vg / V *100% Vg V = 1 - 31 234
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Munroe Francis Richards A.M.Gaudin 2-163050mm
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QAUa. Ua=Q/A
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1ua ua , . v0 .2) ua , G H ;G/H = Const. ,.3) uaH,.Vg ,.
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, vg
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g lgg lg1- k lg =0g=
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nn>2 n lg(1-),lgua lgvg . n. ,.
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3
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eg eg =dV1/dv2:v01(1-01)n1 = v02(1-02)n2n1 =n2= n:
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(2-2-32)::: n=2.39 : n=4.78,,,,.,, (1-02) > (1-02) eg > e0 ,.
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2.3 2.3.1 d1d2d3d1v01v02v03X=d1/2v0